Soil Calculator UK

How Much Topsoil Do I Need?

This topsoil calculator works out exactly how much topsoil you need for any garden project — raised beds, borders, new lawns, or topping up existing beds. Enter your dimensions and fill depth to get instant results in cubic metres, litres, and bag counts for both 25L and 40L bags. Whether you are buying in bulk bags or individual bags from a garden centre, this calculator gives you the right amount first time — no wasted trips, no running short mid-project.

How much topsoil do I need? It depends entirely on the area and depth. A small 1.2m × 2.4m raised bed at 30cm deep needs around 860 litres. A 20m² lawn at 15cm deep needs 3,000 litres. Enter your exact dimensions above and get your answer in seconds.

Planning to seed a lawn after laying topsoil? Use our grass seed calculator to get the right amount of seed. If you're also feeding the soil, our fertiliser calculator works out the exact application rate.

Building raised beds for growing? Our vegetable planting calendar covers 30+ crops with month-by-month sowing and planting dates. See what to plant in March to get started this season.

Recommended Soil Depths by Use

Not sure how deep to fill? Here are the recommended depths for common garden projects.

Frequently Asked Questions

How Much Topsoil for a Lawn or Grass?

Topsoil for grass is one of the most common reasons people use this calculator. Whether you are laying turf, seeding a new lawn from scratch, or top-dressing an existing lawn, the amount of topsoil you need varies significantly by project type.

Topsoil for a new lawn from seed

For the best results seeding a new lawn, you need 10–15cm of good-quality, free-draining topsoil. Avoid heavy clay — a light sandy loam allows roots to establish quickly and gives better drainage. Rake level before sowing, firm gently, and sow on the same day to prevent the surface drying out.

Topsoil for laying turf

Turf needs at least 15cm of prepared topsoil to root into. The surface must be firm and level — use the back of a rake to tamp down any soft spots before laying. On heavy ground, a 15cm layer of screened topsoil over the existing soil is usually sufficient. Use the calculator above: enter your lawn length and width, set the depth to 15cm, and you will get the exact volume in litres and number of bulk bags.

Once your topsoil is down and level, use our grass seed calculator to work out exactly how much seed you need for your lawn area.

Raised Bed Soil Calculator — How Much Soil for a Raised Bed?

Raised beds are the most common reason people search for a topsoil calculator. Here are the exact amounts for popular UK raised bed sizes, calculated at a standard 30cm (12 inch) fill depth using a 60/40 topsoil-to-compost mix.

Money-saving tip: For beds over 500 litres, a bulk bag (approximately 850 litres) is significantly cheaper per litre than individual bags. Most builders merchants and garden centres deliver bulk bags for £40–80 including delivery. Use the calculator above for your exact dimensions — these common sizes are guides only.

What to fill raised beds with

The ideal raised bed mix depends on what you're growing. For vegetables, use 60% screened topsoil and 40% garden compost — this gives good drainage, nutrient content and water retention. For herbs and Mediterranean plants that prefer sharper drainage, add 20% horticultural grit to the mix. For acid-loving plants like blueberries, use ericaceous compost instead of standard garden compost.

Avoid using soil from elsewhere in your garden unless you're sure it's free from perennial weeds like bindweed and couch grass. These will establish in your raised bed and are very difficult to remove once rooted.

Need L-shaped or irregular beds? Try our dedicated raised bed soil calculator — it handles L-shaped layouts, includes the 60/30/10 soil mix breakdown, and shows cost estimates for bags and bulk deliveries.

How Much Topsoil Per Square Metre?

A common question when ordering topsoil in bulk. Here's how it breaks down by depth:

Weight conversion: Topsoil weighs approximately 1.2 tonnes per cubic metre when loose. A standard bulk bag holds about 0.7m³ (roughly 850 litres), weighing around 850kg. If you're ordering by the tonne, one tonne of topsoil is approximately 0.83 cubic metres or 830 litres. Need compost instead of topsoil? The volumes are the same, but compost is lighter — around 0.5–0.7 tonnes per cubic metre.

How to Prepare Garden Soil in Spring

March and April are prime time for soil preparation in the UK. Whether you're filling new raised beds or improving existing borders, getting the soil right now sets up your entire growing season.

New raised beds

If you're building raised beds this spring, fill them at least 2 weeks before planting. This lets the soil settle naturally — you'll lose about 5–10% of the volume as it compacts. Top up after settling, then plant. Use the calculator above to work out exactly how much soil you need, and avoid the common mistake of underordering.

Existing beds and borders

For established beds, add a 5–10cm layer of garden compost on top in early spring. Don't dig it in — let the worms pull it down over the next few weeks. This no-dig approach preserves soil structure and feeds the biology your plants depend on. Use our compost calculator to work out how much you need.

Improving heavy clay soil

If your garden sits on heavy clay (common across much of England), work in 5–8cm of horticultural grit plus 5cm of compost in early spring before the soil dries out and becomes unworkable. Clay soil should be damp but not waterlogged when you work it — if it sticks to your boots in heavy clumps, wait a few dry days.

Soil for container growing

Growing vegetables in pots and containers? Don't use garden soil — it compacts in containers and drains poorly. Use a multi-purpose compost with added perlite for drainage. For larger containers (40L+), a mix of 70% multi-purpose compost and 30% topsoil gives better weight and stability. See our planting calendar for which crops grow best in containers.

Best Soil Mix for Different Garden Projects

Not all projects need the same soil blend. Here's what works best for common UK garden projects.

Tip: When ordering for raised beds, calculate the total volume you need with the calculator above, then split the order: 60% topsoil bags and 40% compost bags. Mix them together as you fill. This is cheaper than buying pre-mixed raised bed soil, and you control the quality of each component.

Types of Topsoil in the UK

Walk into any builders merchant or garden centre and you will find at least three or four different topsoil products on the shelf, each at a different price point. Understanding what separates them saves you both money and frustration. I have used every type below on my own projects, and the difference between cheap unscreened soil and a proper BS 3882 certified product is night and day.

General Purpose Topsoil

This is the workhorse option and what most people mean when they say "topsoil." General purpose topsoil is natural soil that has been screened through a 10-20mm mesh to remove large stones, roots and debris. It is perfectly adequate for filling raised beds, building up low areas, and creating new planting borders. The quality varies enormously between suppliers, so always ask whether it has been screened and what the source is. Expect to pay around £50–70 per bulk bag delivered.

Premium Screened Topsoil

Premium screened topsoil goes through a finer screen (typically 10mm) and is often blended with compost or organic matter before sale. It is noticeably darker, crumblier and more pleasant to work with than general purpose soil. This is what I use for vegetable raised beds where the soil quality directly affects crop yield. Most premium products carry BS 3882 certification, which means they have been independently tested for pH, organic matter content and contamination. Budget £70–100 per bulk bag.

Organic Topsoil

Organic topsoil is premium screened soil that has been enriched with Soil Association certified organic compost. If you are growing vegetables organically and want to be certain there are no synthetic chemical residues in your growing medium, this is the safest choice. It costs more — typically £90–120 per bulk bag — but for a kitchen garden where you are eating what you grow, the peace of mind is worth it.

Sandy Loam Topsoil

Sandy loam is the gold standard soil texture for most garden plants. It drains freely, warms up quickly in spring, and is easy to dig even after heavy rain. If your garden sits on heavy clay (as roughly 40% of English gardens do), importing sandy loam topsoil for raised beds gives your plants a much better start. It is particularly good for root vegetables, herbs and Mediterranean plants that hate sitting in wet soil over winter.

Clay-Based Topsoil

Clay-based topsoil holds moisture and nutrients well, which makes it excellent for trees, shrubs and perennial borders that need consistent moisture through summer. However, it is heavy to work, slow to warm in spring, and can become waterlogged in winter. I would never fill a vegetable raised bed with clay-based topsoil, but for establishing a mixed border of shrubs and perennials it works perfectly well and is usually the cheapest option at £40–60 per bulk bag.

My recommendation: For most raised bed projects, premium screened topsoil blended with 40% garden compost gives you the best balance of structure, drainage and nutrients. Use the calculator at the top of this page to work out your total volume, then split the order accordingly.

How to Improve Your Garden Soil

Buying new topsoil is not always the answer. If your existing garden soil is fundamentally sound but just a bit tired, worn out or poorly draining, improving what you already have is cheaper and often more effective than importing fresh soil on top. Here is my practical approach to soil improvement, based on what actually works in UK conditions.

Test your pH first

Before you do anything else, test your soil pH. A basic soil pH testing kit costs around £8 and takes five minutes to use. Most UK garden plants thrive in a pH range of 6.0-7.0. If your soil is below 5.5 (too acidic), add garden lime at 200g per square metre and re-test after 3 months. If it is above 7.5 (too alkaline), work in sulphur chips at 100g per square metre. There is no point adding expensive compost or topsoil if the underlying pH is wrong — your plants will still struggle regardless.

Adding compost for clay soils

Heavy clay is the most common soil complaint I hear from UK gardeners. The fix is straightforward but requires effort: spread a 75mm (3 inch) layer of well-rotted garden compost over the surface, then dig it into the top 200mm (8 inches) with a garden fork. Do this in autumn or early spring when the clay is moist but not waterlogged. The organic matter opens up the clay structure, improves drainage and feeds the worms that do the long-term soil building for you. Repeat annually for 3 years and you will transform even the heaviest clay into workable soil. Use our compost calculator to work out exactly how much compost you need for your plot.

Adding grit for drainage

If your borders or beds hold standing water after rain, adding horticultural grit improves drainage permanently. Spread 50mm (2 inches) of coarse grit (6-10mm particle size) over the surface and dig it in thoroughly to a depth of at least 200mm. This physically opens up the soil structure and creates air pockets that allow water to drain through rather than sitting around roots. For herb gardens and Mediterranean plantings, I use a 70/30 mix of existing soil to grit — these plants genuinely need sharp drainage to survive a British winter.

Raised beds for problem soil

Sometimes the most practical solution is to build on top of the problem rather than fix it. If your garden sits on solid clay, compacted rubble-filled builder's soil, or contaminated ground, raised beds let you start with a clean growing medium without tackling the underlying issues. A raised bed 300mm (12 inches) deep gives enough root space for virtually any vegetable or flower, and you control exactly what goes into it. Line the base with landscape fabric to prevent weed migration from below, fill with a 60/40 topsoil-compost blend, and you are growing within a weekend. Our mulch calculator can help you work out how much bark mulch to apply on top for weed suppression and moisture retention.

How Much Topsoil Do You Really Need?

One of the biggest mistakes I see people make is guessing their topsoil quantities. Under-ordering means a second delivery charge (typically £30–50 on top of the soil cost), while over-ordering leaves you with an unwanted heap of soil and nowhere to put it. Here are the exact quantities for common UK garden projects, calculated from real dimensions so you can cross-check against the calculator above.

Cost notes: Prices above are based on 2026 UK averages for premium screened topsoil delivered in bulk bags. Individual 25-litre bags from garden centres typically cost £4–6 each, which works out to £160–240 per cubic metre — roughly three times the bulk bag price. For any project over 500 litres, always order bulk bags. For anything over 3 cubic metres, ask for loose tipper delivery which is cheaper still at around £35–50 per cubic metre.

Once you know your project volume, use the calculator at the top of this page to verify the numbers against your exact measurements. If you are also laying turf on top of your new topsoil, our grass seed calculator will help you work out the seeding rate.

Common Topsoil Mistakes (and How to Avoid Them)

After years of helping people with garden soil projects — and making most of these mistakes myself early on — here are the five I see most often. Every single one is avoidable with a little knowledge.

1. Buying unscreened soil

Unscreened topsoil is cheap for a reason. It arrives full of stones, broken glass, plastic fragments, perennial weed roots and sometimes even building rubble. I once took delivery of a "bargain" load of topsoil that contained enough bricks to build a small wall. Unscreened soil is fine for backfilling behind a retaining wall or building up ground levels where nothing will be planted, but for any growing project, always insist on screened topsoil — ideally to 10mm. The extra £15–20 per bulk bag is money well spent when you are not picking stones out of your carrot bed for the next three years.

2. Not enough depth for raised beds

A raised bed filled to only 150mm (6 inches) looks adequate on the day you fill it, but topsoil settles by 10-15% over the first few weeks as it compacts under its own weight and rain. After settling, your 150mm bed is now 130mm — barely enough for lettuce, let alone carrots or potatoes. Always fill raised beds to a minimum of 300mm (12 inches) and accept that they will settle to around 260mm. If you are growing root vegetables, go to 400mm. The extra soil costs perhaps £20–30 more per bed, but the difference in crop performance is enormous.

3. Not testing pH before planting

I have lost count of the number of gardeners who have spent hundreds of pounds on topsoil and compost, planted out their vegetables, and then watched everything struggle. When we test the soil, it turns out to be pH 8.0 or higher — far too alkaline for most vegetables. This is especially common when using reclaimed topsoil from building sites, which is often contaminated with lime from concrete and mortar. A simple pH test kit costs about £8 and takes 5 minutes. Test before you plant, not after everything has failed.

4. Working or compacting wet soil

Walking on or digging wet soil — particularly clay-based topsoil — destroys its structure by squeezing out the air pockets that roots and soil organisms need. Once compacted, soil becomes almost impermeable to water and roots, and it can take years to recover. The rule is simple: if the soil sticks to your boots in heavy clods, stay off it. Wait for a dry spell, then work the soil when it is damp but crumbly. If you need to access beds during wet weather, lay scaffold boards across the surface to spread your weight.

5. Mixing incompatible soil types

Layering pure sand on top of clay soil (or vice versa) without mixing them together creates a perched water table — water pools at the boundary between the two layers instead of draining through. This is worse than leaving the clay alone. If you are improving clay soil, always dig the amendment (compost, grit or sandy loam) into the existing soil thoroughly to a depth of at least 200mm. Similarly, if you are adding fresh topsoil on top of an existing bed, fork the surface of the old soil before laying new soil on top so the two layers can integrate naturally.

More Topsoil Questions Answered

Best Topsoil & Raised Bed Soil UK 2026

Whether you're filling raised beds, levelling a lawn or improving borders, these are the top-rated soil products available in the UK.

Links above are affiliate links — we may earn a small commission at no extra cost to you.

How Much Topsoil for a New Lawn?

"How much topsoil do I need for grass?" is one of the most common questions we get, and the answer depends on whether you are sowing seed or laying turf — and what is underneath.

Topsoil depth for a new lawn from seed

Grass seed needs a minimum of 100mm (4 inches) of quality topsoil to establish a healthy root system. At 100mm, roots reach full depth within 6–8 weeks in spring, but drought resistance will be limited. For a lawn that stays green through a dry July, aim for 150mm (6 inches). This gives roots enough depth to access moisture even when the top 50mm dries out completely.

For a typical UK rear garden of 50m², that works out to:

• At 100mm depth: 5.0m³ (5,000 litres) — 6 bulk bags or roughly £300–420
• At 150mm depth: 7.5m³ (7,500 litres) — 9 bulk bags or roughly £450–630

Use the calculator at the top of this page with your exact lawn dimensions to get a precise figure.

Topsoil depth for laying turf

Turf rolls arrive with their own root zone — typically 15–20mm of soil attached to the grass. Because of this, you can get away with less topsoil underneath: 50–75mm (2–3 inches) is the minimum, though 100mm gives better long-term results. The critical step is ensuring the topsoil is raked level and firmed before laying the turf. Any hollows or humps will show through within weeks as the turf settles.

Preparation steps for a new lawn

Before ordering topsoil for a new lawn, prepare the ground properly. This saves you time, money and heartache later:

1. Remove existing debris — clear stones, old turf, weeds and any building rubble down to subsoil level.
2. Grade the subsoil — rake the subsoil roughly level and break up any compacted areas with a garden fork. This prevents water pooling at the topsoil/subsoil boundary.
3. Spread your topsoil — tip and spread in layers, working across the area. Do not dump everything in one spot and try to drag it flat.
4. Rake level — use a landscape rake to create a smooth, even surface. Check with a long straight edge or taut string line.
5. Firm and re-rake — walk over the entire area with overlapping steps (called "heeling in"), then rake again to remove footprints. Repeat once more for a fine, firm seedbed.
6. Wait 7–10 days — let the soil settle before sowing or turfing. Top up any low spots that appear.

Once your topsoil is down and settled, use our grass seed calculator for exact seeding rates, or our turf calculator to work out how many rolls you need.

Topsoil Types — Which Do You Need?

Not sure which type of topsoil to order? This quick comparison covers the four main types you will find at UK builders merchants and garden centres, with realistic 2026 pricing.

Which should you pick? For most garden projects — lawns, borders, raised beds — screened topsoil at £25–40/tonne is the right choice. Upgrade to premium blended if you are filling vegetable beds and want to skip the step of mixing in your own compost. Use unscreened only for non-growing areas where you just need to raise the ground level. Sandy loam is worth the premium if you garden on heavy clay and want to give plants a fighting chance at drainage.

How Deep Should Topsoil Be?

Getting the depth right is just as important as getting the volume right. Too shallow and roots run out of growing space. Too deep and you waste money on soil you did not need. Here is a definitive depth guide for every common garden project.

Remember the settling rule: Fresh topsoil settles by 10–15% within the first few weeks as it compacts under its own weight and rainfall. If your project needs 300mm of finished depth, fill to 330–345mm initially to allow for this. The calculator above gives you the volume for your target depth — just add 10–15% to account for settlement.

Topsoil Calculator — Bags vs Bulk Bags vs Loose Loads

Once you know how much topsoil you need, the next decision is how to buy it. There are three main delivery options in the UK, and choosing the right one can save you hundreds of pounds on larger projects.

25-litre bags (small jobs)

Standard bags from garden centres and DIY stores — typically £5–7 each. Easy to carry, fit in a car boot, and handy for topping up a single raised bed or filling a few pots. The downside is cost: at £5 per 25-litre bag, you are paying roughly £200 per cubic metre. That is three to four times what bulk delivery costs. Only use bags if you need less than 200 litres (8 bags) — beyond that, bulk bags are always cheaper.

Bulk bags (medium jobs)

The most popular option for garden projects. A standard bulk bag holds 850–1,000 litres (0.7–0.85m³) and weighs around 900kg. Prices range from £50–100 per bag including delivery, depending on topsoil grade. Most builders merchants and garden centres offer next-day or nominated-day delivery. You need a firm, level surface for the driver to place the bag — driveways work well, lawns do not (the weight will leave a deep impression). One bulk bag is enough for a single 2.4m × 1.2m raised bed filled to 300mm.

Loose tipper loads (large jobs)

For projects over 3 cubic metres — new lawns, multiple raised beds, or a full garden renovation — a loose tipper delivery is the cheapest per-tonne option. Prices run £35–50 per cubic metre depending on your location and the supplier. Minimum orders are usually 3–5 cubic metres. You need clear vehicular access (the lorry is large) and enough space for the heap — 5m³ of topsoil makes a pile roughly 2m wide, 2m deep and 1.5m high. The soil is tipped directly, so you will need a wheelbarrow and strong arms (or a willing helper) to move it to where it is needed.

Tips for Buying Topsoil in the UK

Topsoil quality varies wildly between suppliers, and a bad batch can set your garden project back months. These are the practical checks I run every time I order topsoil, based on years of trial and (expensive) error.

Ask for BS 3882 certification

BS 3882 is the British Standard for topsoil quality. It guarantees the soil has been laboratory-tested for pH, organic matter content, stone percentage, particle size and contamination levels. Any reputable supplier will have a current BS 3882 certificate and should show it on request. If they cannot — or will not — find a different supplier. This is especially important for vegetable-growing projects where contaminated soil is a genuine health concern.

Check for weed contamination

Before committing to a bulk order, ask for a sample bag or inspect the heap at the yard. Look for white, fleshy root fragments — these are perennial weeds like bindweed, couch grass or ground elder. Even a small piece of root will regrow into a mature plant within weeks. Weed-free topsoil does exist, but it costs more because it has been properly processed. The alternative — spending the next five years pulling bindweed out of your raised beds — is far more expensive in time and sanity.

Order 10–15% more than your calculation

Delivered topsoil settles as it compacts under its own weight and absorbs rainfall. Budget for 10–15% more than the calculator tells you, particularly for raised beds that you want filled to the brim. It is far cheaper to order an extra half-bag at the time of delivery than to arrange a second, separate delivery to top up the shortfall later. Most suppliers charge £30–50 per delivery regardless of quantity, so one larger order beats two smaller ones every time.

Time your purchase

Spring (March–May) and autumn (September–October) are the ideal buying windows. In spring, the ground is workable and you can plant or sow immediately after spreading. In autumn, fresh topsoil benefits from winter rain and frost, which breaks down clods and helps it settle before the spring growing season. Avoid ordering in mid-winter when frozen ground makes spreading impossible and heavy delivery lorries churn up wet lawns and driveways.

Compare prices per tonne, not per bag

Suppliers quote prices in confusingly different units — per 25L bag, per bulk bag, per tonne, per cubic metre. To compare like-for-like, always convert to price per tonne. A bulk bag weighs roughly 850–1,000kg (just under 1 tonne), so the bulk bag price is a good approximation of the per-tonne cost. Individual 25L bags from garden centres cost £4–7 each, which is £190–340 per tonne — three to five times the bulk price. For any project needing more than 500 litres, bulk delivery pays for itself immediately.

More Topsoil Questions

What Type of Soil Do I Need? Quick Decision Guide

Not sure which soil product to buy? Use this quick-reference guide to match your garden project to the right soil type, depth and budget. Every figure below is based on UK 2026 pricing and the depth recommendations from the tables above.

Still not sure? For most garden projects, start with premium screened topsoil at £70–100 per bulk bag. Mix in 40% garden compost for raised beds, or use it neat for lawns and borders. Use the calculator at the top of this page with your exact dimensions — it gives you the volume in cubic metres, litres and bags so you can order with confidence.

Planning a Bigger Garden Project?

Soil is usually just one part of a larger build. Here are the calculators our users pair most often with the soil calculator:

• New lawn? Work out how much grass seed you need, then check our fertiliser calculator for first-feed rates.
• Raised beds? Use the raised bed calculator for timber + soil volumes, and our compost calculator for the organic mix layer.
• Mulching beds? Our mulch calculator and bark chippings calculator cover every UK bark and wood chip product.
• Hard landscaping? Try the gravel calculator, concrete calculator, or sub-base calculator for patios, paths and foundations.
• When to plant? Check your last frost date and browse the planting calendar for month-by-month sowing guides.
• Feeding your lawn? Our lawn feed calculator works out exactly how much feed you need per application.

How Much Soil Do I Actually Need?

The honest answer is always the same sum: area × depth = volume. Measure your bed in metres, pick a depth in metres, multiply the two, and you have cubic metres. Multiply cubic metres by 1,000 and you have litres — which matches how soil is actually sold in the UK.

A worked example: a raised bed that’s 1.2m × 2.4m, filled to 30cm deep, works out at 1.2 × 2.4 × 0.30 = 0.864 cubic metres, or 864 litres. The calculator at the top of this page does the sum for you in whichever units you prefer, but the logic doesn’t change.

Always order 5–10% more than the calculator says. Soil settles, some of it sticks to the bag or wheelbarrow, and running out 80% through the job is genuinely miserable — especially if your supplier has a minimum delivery charge. For raised beds in their first year, add 10–15% because the fill will slump noticeably as organic matter breaks down.

Depth Matters More Than Area

Most first-time buyers over-focus on the footprint of the bed and under-think the depth. Depth is where costs balloon — doubling the depth doubles the soil bill. Here’s what you actually need for the most common UK garden jobs:

One thing the depth table doesn’t show: you almost never need to replace your existing garden soil wholesale. Most of the time you’re topping up, not filling from scratch.

Bags vs Bulk Bags vs Loose Delivery — When Each Makes Sense

The single biggest lever on your soil budget is how you buy it. The price per litre drops roughly 50% each time you step up a tier:

• Under 100 litres — small bags. 50L bags at £4–7 each from a garden centre. Fine for a pot refresh, a small border top-up or the last 50L of a bigger order. Easy to carry through a side gate.
• 100–500 litres — bulk bag. A 730L bulk bag costs £60–100 delivered. That’s the same volume as 30–40 small bags, which would cost you £140–280 at garden centre prices. You need hard standing for the crane or forklift to drop it — driveways and paving, not lawn.
• Over 500 litres — loose tipped delivery. The cheapest option per litre, usually £35–50 per cubic metre. The lorry tips it onto your drive and you shift it yourself. Best when you’ve got access, a couple of hours, and a wheelbarrow.

There’s one more saving most guides miss: local quarries and builders’ merchants are typically 20–30% cheaper than garden centres for the same spec of screened topsoil. Ring round three places before you order — ask for a price on BS 3882 multipurpose, delivered, inside your postcode radius. The price variance is huge.

What Kind of Soil for What Job?

The labels at the garden centre are confusing on purpose. Here’s what each product actually is and when to buy it:

• Topsoil — general-purpose screened natural soil. Your default for raised beds, borders and lawn prep. £4–6 per 50L bag or £60–90 per bulk bag.
• Multi-purpose compost — not soil. It’s a peat-free growing medium for seed trays, pots and mixing into existing soil. Holds moisture well but shrinks in volume, so don’t use it as bulk fill.
• Rose and shrub compost — loam-based, heavier, contains more clay and nutrients. Ideal for planting holes for clematis, roses, magnolias and anything that wants a richer, moisture-retentive root zone.
• Ericaceous compost — acidic (pH 4.5–5.5). The only right choice for rhododendrons, azaleas, camellias, blueberries and cranberries. Normal compost will kill these plants slowly over a couple of seasons.
• John Innes No. 1, 2 and 3 — the traditional sterilised loam-based recipes. No. 1 is light (for seedlings), No. 2 is standard potting mix, No. 3 is the richest (for hungry container crops like tomatoes and long-term pot shrubs). John Innes holds nutrients for longer than multi-purpose and doesn’t dry out as quickly.
• Peat-free vs peat — peat-free is now the legal retail standard after the 2026 ban. It drains faster and dries out quicker on the surface, so water more often and feed earlier. We covered the full switchover guidance in Friday’s Masterpiece newsletter — the short version: look for brands blending wood fibre with loam or wool fibre.

Doing a border refresh or topping up existing beds? Most of the time you want compost, not topsoil — try the compost calculator for the right volume.

The £30 Mistake Most First-Time Buyers Make

It happens every spring. Someone builds their first 1.2m × 2.4m × 0.3m raised bed, works out it’ll take about 864 litres of soil, and drives to the garden centre. They load 18 bags of 50L topsoil at £6 each into the car (in two trips, because it doesn’t all fit), pay £108, and lug the lot through the side gate bag by bag.

One 730L bulk bag from a local supplier would have cost them roughly £70 delivered. Add one 50L top-up bag for £6 and a couple of bags of compost to mix in, and the total is around £85 — delivered to the driveway, dropped by crane, no 18-bag lugging session. That’s £23 saved and about two hours of your life back.

The tipping point is about 250 litres. Below that, bagged soil from the nearest shop is the right call. Above it, ring a local supplier. It’s that simple. If you’re specifically filling a raised bed, the raised bed calculator also gives you the timber volume so you can plan one delivery for both.

Top 3 Things Most Soil Guides Get Wrong

Three stubborn myths to bin before you order:

1. “Soil” and “compost” aren’t interchangeable. Compost is a soil improver — concentrated organic matter you mix in or top-dress with. Topsoil is the bulk fill. Filling a raised bed with pure compost might feel generous, but it’ll shrink by 20–30% in the first year and leave your plants slumped below the rim. Always use topsoil (or a 60:40 topsoil-compost blend) for bulk filling, and save pure compost for the top 75–100mm.
2. New raised beds slump 10–15% in the first year. This is normal and unavoidable — organic matter in the fill breaks down, soil compacts after the first heavy rain, and the level drops. Over-fill slightly when you build, or plan on topping up with a bag or two of compost the following spring. Builders forget this constantly.
3. You rarely need to swap clay soil for topsoil. Clay is actually full of nutrients — the problem is drainage and workability. Forking in horticultural grit (about a bucket per square metre) plus 75mm of compost over the top, dug in once, will transform a claggy border for a fraction of the cost of a full soil swap. Give it a winter to settle and you’ll have better soil than bagged topsoil from a garden centre.

Get those three right and you’ll spend less, plant healthier, and skip the annual “why’s my bed sinking?” panic. Use the calculator at the top of this page for your exact numbers, and ring a local quarry before you trust garden centre pricing.