Bark Chippings Calculator

This free calculator estimates bark chippings for garden paths, play areas, driveways, decorative borders or weed suppression. It supplies planning defaults for non-play projects. For a play area, enter the verified depth from the equipment specification and chosen product certificate or test documentation before calculating litres, bags and bulk bags.⁵⁴

The formula is simple: length × width × depth = volume. The calculator converts your depth from millimetres to metres, then gives you the total in cubic metres and litres. Since UK retailers commonly sell bark chippings by volume²³ (unlike aggregates, which are often sold by weight), the results are in litres and bags rather than tonnes.

Bark chippings vs bark mulch: This calculator is for bark chippings, the chunky, longer-lasting pieces used for paths, play areas and decorative coverage. If you’re mulching garden beds to enrich the soil, our bark mulch calculator is designed for that purpose.

The planning depth depends on the project. For a play area, this table does not set a safety depth: use the equipment specification, chosen product certificate or test documentation, and applicable BS EN 1176 and BS EN 1177 requirements.⁵⁴

If you’re laying bark chippings in a children’s play area, you must use certified play bark that meets BS EN 1177, the European standard for impact-absorbing playground surfacing. Standard bark chippings are NOT suitable for play areas.⁴

What actually governs your depth

• Equipment: use the equipment manufacturer’s specification and applicable BS EN 1176 requirements to establish the free-fall height and impact area⁵
• Surface: use the chosen product certificate or test documentation and applicable BS EN 1177 requirements to establish the installed depth⁴
• Impact area: use the equipment manufacturer’s specified impact area and applicable BS EN 1176 requirements. The required dimensions depend on the equipment and its free-fall height; do not apply a fixed extension to every installation⁵
• Installation and maintenance: follow the product certificate and supplier or manufacturer instructions for installation allowances, inspection and replenishment; do not apply a generic calendar or percentage⁴

Play-surface checks before calculating

Important: Enter only the depth verified from those documents. Use their installation and maintenance allowances rather than adding a generic extra depth or percentage.⁵⁴

Bark chippings make excellent, low-cost garden paths. They’re softer underfoot than gravel, look natural in garden settings, and are easy to lay yourself in an afternoon.

How to lay a bark chippings path

• 1. Mark out your path: use string lines or a garden hose to define the edges. Standard width is 0.9–1.2m for a single-person path.
• 2. Excavate to 100mm deep: remove turf and topsoil. If drainage is poor, dig 25mm deeper and add a layer of coarse gravel.
• 3. Lay weed membrane: heavy-duty landscape fabric prevents weeds growing up through the bark.
• 4. Install edging: timber edge boards, log rolls or metal edging stop the bark spreading onto borders and lawns. This is essential. Without edging, bark migrates everywhere.
• 5. Spread bark chippings to 75mm: rake level and compact lightly by walking along the path.

Need to calculate the sub-base for a more permanent path? Our MOT Type 1 calculator works out hardcore quantities, and the gravel calculator handles decorative stone surfaces.

A standard bulk bag contains approximately 1 cubic metre (1,000 litres) of bark chippings. The area it covers depends on the depth you lay.

They look similar but serve different purposes. Choosing the wrong one wastes money and gives poor results.

Bark chippings prices vary by grade, supplied volume, supplier and location. Treat the figures below as illustrative.

Delivery and access charges vary. Ask for current written quotes that identify the same product grade and supplied volume, with all delivery and access charges shown, before comparing formats.

Whether you call it bark mulch, bark chippings or simply “bark,” the calculation is the same: length × width × depth = volume. The calculator above works for both. Just select your project type and enter your measurements. The difference is in the product you buy, not the maths.

For most garden mulching jobs, you need a layer between 50mm and 100mm deep. Thinner layers let weeds through; thicker layers waste money and can smother shallow-rooted plants. Here is how much bark mulch you need per square metre at each common depth:

• 50mm deep: 50 litres per m² (decorative borders, light weed suppression)
• 75mm deep: 75 litres per m² (paths, solid weed barrier with membrane)
• 100mm deep: 100 litres per m² (driveways, heavy-traffic areas)

What area does 1,000 litres of bark cover? A standard bulk bag holds roughly 1,000 litres (1 cubic metre). At 50mm deep it covers 20 m², at 75mm deep it covers 13.3 m², and at 100mm deep it covers 10 m². For a typical 4m × 3m border at 50mm depth, one bulk bag is enough with a little left over for top-ups.

How much does 100 litres of bark chippings cover? A single 100-litre bag covers 2 m² at 50mm deep, 1.33 m² at 75mm deep, or 1 m² at 100mm deep. Most garden centre bags are 80 litres rather than 100, so an 80L bag covers about 1.6 m² at 50mm or just over 1 m² at 75mm.

Bark Mulch vs Bark Chippings: What’s the Difference?

The terms are often used interchangeably, but they are different products. Bark mulch is finer, shredded bark (typically 5–20mm pieces) that breaks down within one to two seasons, feeding the soil as it decomposes. It is ideal for garden beds, borders and around tree bases where you want to improve soil structure over time.

Bark chippings are coarser, chunkier pieces (20–60mm) that last two to four years before needing replacement. They hold their shape better, stay in place on paths, and are the right choice for walkways, play areas, driveways and any surface that takes foot traffic. If you need bark for garden beds, our mulch calculator gives tailored results for that job.

How Many Litres of Bark Per Square Metre?

The number of litres you need per square metre depends entirely on the depth. Use this quick-reference table to estimate quantities before you buy:

For example, a 6m × 2m path at 75mm deep needs 900 litres: 12 bags of 80L or just under one bulk bag. Always round up and add 10% for uneven ground and settling.

Top-up tip: Both bark mulch and bark chippings settle and decompose over time.¹ Finer bark mulch loses roughly 30–40% of its volume in the first year, while coarser chippings lose around 15–25%. Budget for an annual top-up layer of 25mm to maintain effective coverage and keep weeds at bay. Laying a heavy-duty weed membrane underneath extends the life of any bark product significantly.

Not all bark chippings are the same. The type you choose affects how long it lasts, what it looks like, and whether it’s suitable for your project. I’ve laid every type listed below in real UK gardens, and the differences matter more than most people realise.

Ornamental bark is the fine-grade option (10–25mm), typically made from pine or spruce. It gives a neat, uniform appearance that suits front gardens and show borders. The downside is it decomposes faster than coarser grades. Expect to replace it every 12–18 months. It also tends to blow around in exposed spots because the pieces are so light.

Play bark is specifically manufactured and tested to meet BS EN 1177, the UK and European standard for impact-absorbing playground surfacing. The particles are engineered to be free of splinters, sharp edges and contaminants, and the material must prove its shock-absorption capacity at defined depths. You cannot substitute standard bark chippings for play bark in a children’s play area. Before comparing products, verify the chosen live listing and supplier documentation against the project and equipment requirements, then compare current written quotes on the same supplied-volume, delivery and access basis.

Composted bark is bark that has been partially broken down before sale. It has a darker, richer colour and a finer texture than fresh bark. Because the decomposition process has already started, it enriches the soil faster, which makes it a good choice for border beds where you want both weed suppression and soil improvement. It settles more quickly than fresh bark, so lay it 10–15% deeper than usual. Our soil calculator can help if you’re also adding topsoil to the same beds.

Bark nuggets are the largest grade: chunky pieces typically 40–80mm. They look striking in large borders, around specimen trees and in modern landscaping schemes. Because of their size, they take the longest to decompose (3–5 years) and stay in place well even on gentle slopes. The trade-off is they’re less comfortable to walk on, so they’re not ideal for paths.

Wood chip is often confused with bark chippings, but it includes the inner wood as well as the bark. Arborists produce it as a by-product of tree surgery, and you can sometimes get it free or very cheaply from local tree surgeons. It decomposes faster than pure bark and can temporarily lock up nitrogen in the soil, so keep it away from young or shallow-rooted plants. It works well for informal woodland paths and utility areas.

Laying bark chippings is a straightforward weekend job. I’ve done this dozens of times for clients and in my own garden, and the preparation is what separates a path that looks great for years from one that’s overrun with weeds in three months.

Step 1: Clear the area

Remove all existing weeds, grass and debris from the surface. For established weeds, dig out the roots rather than just cutting the tops. Perennial weeds like bindweed and couch grass will push straight through bark if the roots are left intact. If you’re covering a large area of lawn, use a spade to strip the turf first. Rake the soil level and remove any stones larger than 50mm.

Step 2: Lay weed membrane

This step is essential for paths, driveways and play areas. Use a heavy-duty woven geotextile membrane rated at a minimum of 100g/m². The cheap 50g/m² fabric tears within a year. Overlap sheets by at least 150mm and secure with galvanised membrane pegs every 300mm along the edges. For borders around existing plants, cut X-shaped slits where the plants emerge and fold the flaps neatly around the stems.

Step 3: Install edging

Without edging, bark chippings migrate into your lawn, borders and everywhere else within weeks. Options include timber edge boards (pressure-treated, at least 100mm tall), log rolls, metal lawn edging or recycled plastic edging. Pin the edging securely into the ground. It needs to be at least as tall as your planned bark depth. For curved paths, flexible metal or plastic edging bends to shape.

Step 4: Spread bark to the correct depth

Tip the bark onto the membrane and spread it with a landscaping rake. The planning depth depends on the project: 50mm for decorative borders and 75mm for garden paths and weed suppression. For a play area, use the installed depth and measurement method from the equipment specification, chosen product certificate or test documentation, and applicable BS EN 1176 and BS EN 1177 requirements.⁵⁴

Step 5: Compact lightly

For paths and driveways, walk along the surface to press the bark down gently. This helps it settle and reduces the amount of initial sinkage. Do not use a roller or plate compactor: you want the bark to remain loose enough to drain freely. For a play area, follow the installation, compaction, inspection and replenishment instructions in the equipment specification and chosen product documentation; do not apply the path method or a generic waiting period.⁵⁴

Need to work out how much bark this will take? Use the calculator at the top of this page, or check our mulch calculator if you’re covering garden beds with finer bark mulch.

The total delivered cost depends on the product grade, supplied volume, delivery method, location and access. Compare current written quotes for the same grade and volume, with every delivery and access charge shown.

Price breakdown by buying format

Individual bags: Verify the chosen product’s stated pack volume and grade. Ask whether the quote covers collection or delivery and record the total quantity supplied before comparing it with bulk-bag or loose options.

Bulk bags: Verify the chosen product’s stated filled volume and grade. Ask for a written quote showing delivery, unloading and access requirements, then compare the total delivered cost with the same grade and supplied volume in other formats.

Loose loads (tipped delivery): Ask local suppliers for written quotes stating the product grade, supplied volume, delivery charge and vehicle-access requirements. Compare those terms with bagged and bulk-bag quotes for the same grade and volume.

Project cost examples

Budget note: Treat these figures as illustrative; base your budget on current supplier quotations for your site.

I’ve seen these same mistakes repeated on hundreds of garden projects. They are all easy to avoid if you know what to look for.

1. Laying bark too shallow

The most common mistake by far. Bark chippings laid at 25–30mm deep look fine on day one, but within weeks you can see soil through the gaps, weeds push through, and the coverage looks patchy. The minimum effective depth for weed suppression is 50mm, and for paths 75mm is the standard. For a play area, the calculator does not recommend a depth: enter only the value verified from the equipment specification, chosen product certificate or test documentation, and applicable BS EN 1176 and BS EN 1177 requirements.⁵⁴

2. Skipping the weed membrane

Without a membrane underneath, weeds grow up through the bark within a season, and the bark gradually mixes into the soil below. A heavy-duty woven membrane (100g/m² minimum) is a one-time cost that saves years of weeding. The cheap non-woven fabrics degrade in sunlight and tear easily. Spend the extra £10–£15 on a proper geotextile. The only exception is borders where you want the bark to break down and feed the soil, but even then, persistent weeds will be a problem.

3. Piling bark against plant stems

Bark heaped against the stems of shrubs, roses and trees traps moisture against the bark (the plant bark, not the chippings). This creates ideal conditions for fungal diseases like collar rot, which can kill established plants. Always leave a 50–75mm gap between the bark chippings and the base of any plant. Pull the chippings back to create a small ring of bare soil around each stem. This also helps rainwater reach the roots rather than running off the bark surface.

4. Choosing bark by product name alone

Choose the bark grade from the project requirements and chosen supplier’s specification. Where impact attenuation is required, verify the equipment requirements and the chosen product documentation before ordering. For every project, compare current written quotes for suitable products using the same supplied volume and including delivery and access charges; do not infer the result from the product name.

5. Not topping up annually

Bark chippings are a natural material. They decompose. In a typical UK climate, standard bark breaks down by 25–30% per year. A path laid at 75mm deep will be around 50mm after one year and barely 35mm after two, at which point weeds break through, it looks thin, and the membrane starts showing. Set a reminder each spring to check depths and add a top-up. For a play area, ignore this general garden schedule and follow the inspection and replenishment instructions in the governing equipment and product documents.⁵⁴