Fencing Calculator

How Many Fence Panels Do I Need?

This free fencing calculator works out exactly how many fence panels, posts and bags of Postcrete you need for any garden fence. Enter your total fence run in metres or feet, choose your panel size, and get an instant materials list — no guesswork, no wasted trips to the timber yard.

The calculator divides your fence run length by the panel width (standard UK panels are 1.83m / 6ft wide) and rounds up, because you can't buy half a panel. It then adds one more post than the number of panels (you need a post at each end plus one between every panel), plus extra posts for corners and gate openings.

Planning more garden projects? Our concrete calculator works out ready-mix quantities for shed bases and paths, and the gravel calculator handles sub-base and decorative stone.

UK Fence Panel Sizes

Standard fence panels in the UK come in set widths and heights. Here are the most common options available at builders' merchants and DIY stores.

How Deep Should Fence Posts Be?

As a rule, fence posts should be buried at least 600mm (2ft) below ground level. This gives enough anchorage to resist wind loads, especially for a 1.83m (6ft) high fence. For exposed or windy locations, go deeper to 750mm.

The total post length you need depends on your panel height plus the buried depth. For a standard 6ft fence, you need 2.4m (8ft) posts — that's 1.83m above ground and roughly 600mm below.

How Much Postcrete Per Fence Post?

Postcrete is a fast-setting post mix that sets in about 10 minutes. For a standard 100mm timber post in a 300mm wide hole at 600mm depth, you need 2 bags of 20kg Postcrete per post. This is the standard recommendation from most UK fencing suppliers.

If you're using concrete H-posts, you don't need Postcrete — H-posts are designed to be slotted into the ground or set in a standard concrete mix.

Timber Posts vs Concrete Posts

Both timber and concrete fence posts are widely used in the UK. Here's how they compare.

Do I Need Gravel Boards?

Gravel boards sit between the ground and the bottom of your fence panel. They're not essential, but they're one of the best things you can do to extend the life of your fence. Without one, the bottom of the panel sits directly on damp soil — and rot starts within 2–3 years.

A gravel board lifts the panel off the ground by 150mm (6 inches), keeping it dry. Standard gravel boards are 1.83m (6ft) long — the same width as the panels. You need one gravel board per panel gap, so the quantity matches your panel count.

Concrete vs timber gravel boards: Concrete versions last indefinitely but cost more (£8–£12 each). Timber gravel boards are cheaper (£4–£7) but will eventually need replacing — though they're much cheaper than replacing a full fence panel.

Fence Height Rules & Planning Permission

In England and Wales, you can build a garden fence up to 2 metres (6.5ft) high without planning permission under permitted development rights. However, if your fence is next to a road, footpath or public highway used by vehicles, the maximum height without planning permission drops to 1 metre (3.3ft).

Additional restrictions may apply if your property is a listed building, in a conservation area, or has specific conditions on the original planning permission. Always check with your local council planning department if you're unsure.

Frequently Asked Questions

Types of Garden Fencing in the UK

Not all fence panels are created equal. I have used most of these over the years, and the right choice depends on your budget, how exposed your garden is, and whether you want full privacy or something more open. Here is a straightforward comparison of the six most common types you will find at UK timber merchants and DIY stores.

Lap Panels

Lap panels are the most popular choice in the UK, and for good reason. They are the cheapest option at £20–£35 per 1.83m panel, they come in all four standard heights, and you can pick them up from any builders' merchant or DIY store. The horizontal slats overlap each other, which gives you full privacy. The downside is durability — in an exposed garden, a lap panel might only last 8 years before the thin slats start splitting. I always recommend pressure-treated panels over dip-treated ones. The extra £5–£10 per panel adds years to their life.

Closeboard Panels

Closeboard is what I use in my own garden. The vertical featherboard slats are thicker than lap panel slats, and they overlap tightly, which means better wind resistance and a much longer lifespan of 15–20 years. At £35–£55 per panel, they cost more upfront, but when you spread the cost over the years, they are actually cheaper than replacing lap panels every decade. Closeboard panels also look more substantial — they have a proper back frame with horizontal rails, and individual boards can be replaced if one gets damaged.

Featherboard (Feather Edge)

Featherboard fencing is not sold as pre-made panels. Instead, you buy individual feather edge boards (tapered timber boards typically 100mm or 125mm wide) and nail them to horizontal arris rails fixed between your posts. This is the traditional method of building a fence, and it is the best option for sloping ground because each board follows the gradient naturally. You also get complete control over the height. On flat ground, it is more labour-intensive than fitting pre-made panels, but the finished fence is stronger and lasts 15–25 years with proper treatment.

Hit-and-Miss Panels

Hit-and-miss panels have alternating boards on each side of the frame, so there is no direct line of sight through the fence, but air can still flow between the boards. This makes them brilliant for exposed, windy gardens where a solid panel would act like a sail and get blown down. They cost £40–£65 per panel, but they last as long as closeboard and rarely need replacing after storms. If wind is a real problem in your garden, hit-and-miss is the answer.

How to Install a Fence — Step by Step

I have put up more fences than I can count, and the process is the same every time. If you follow these steps and take your time with the posts, the panels are the easy part. Here is the method I use for standard 1.83m (6ft) panels with timber posts.

Step 1: Mark Out Your Post Positions

Start from one end of your fence line and measure 1.83m intervals — one mark for each post. You need a post at each end of the run, one between every pair of panels, and an extra post at each corner. Use string and pegs to keep a straight line. For a 10-metre fence run, you will have 7 post positions (6 panels at 1.83m each = 10.98m of panels, trimming the last panel to fit).

Step 2: Dig Post Holes

Each hole should be 300mm in diameter and 600mm deep as a minimum. For exposed or hilltop gardens, go to 750mm. I use a manual post hole digger for most jobs — it is faster than a spade and gives you a cleaner hole. If you are doing more than 10 posts, hiring a petrol post hole borer for the day (around £45–£65) saves your back and halves the time. Make sure the bottom of each hole is firm and level.

Step 3: Set the First Post

Stand the first post in its hole, check it is vertical with a spirit level on two adjacent faces, and brace it in position. Pour one bag of Postcrete around the post, add the recommended amount of water (usually 1–2 litres), then add the second bag and more water. Postcrete sets in about 10 minutes, so you can work quickly along the line. Use our concrete calculator if you prefer to mix standard concrete instead — you will need roughly 0.04 cubic metres per post hole.

Step 4: Fit Gravel Boards

Before hanging panels, fix a gravel board between each pair of posts at ground level. Concrete gravel boards slot into the grooves of concrete H-posts. For timber posts, screw a gravel board clip to each post at ground level, then drop the board in. The board is 1.83m long and 150mm high — it lifts the panel off the damp soil and can extend panel life by 5–10 years.

Step 5: Hang Your Panels

With timber posts, use galvanised panel clips (also called fence panel brackets) screwed to the post face. Fit two clips per side, per panel — one at the top and one at the bottom of the panel. Lift the panel into position, resting it on the gravel board, and screw through the clip into the panel frame. For concrete H-posts, simply slide the panel down into the H-shaped grooves. This is why concrete posts make future panel replacement so straightforward.

Step 6: Cap the Posts and Treat

Once all panels are in, fit a post cap to the top of every timber post. The cap sheds rainwater away from the exposed end grain, which is the most common point where rot starts. Then apply a coat of exterior fence treatment or preservative to any cut ends. I use a spirit-based preservative on the cut timber and then a water-based fence treatment over the whole thing for UV protection. The total cost for post caps and treatment on a 10-metre fence is around £15–£25 — a tiny outlay that adds years to the fence.

How Much Does a Garden Fence Cost in 2026?

The total cost of a garden fence depends on three things: the type of panel, the length of the fence run, and whether you are doing it yourself or hiring someone. Here are realistic UK prices for 2026, based on materials only (DIY installation). Labour typically adds £30–£50 per panel on top.

What is included in these prices: Panels, timber posts (100mm, 2.4m long at £8–£15 each), Postcrete (2 bags per post at roughly £5 per bag), gravel boards (£4–£7 each), and post caps (£1–£2 each). Prices are based on typical UK builders' merchant rates in spring 2026.

Ways to Save Money on Fencing

The single biggest saving is doing it yourself. Professional installation adds £30–£50 per panel, which on a 20-metre fence means £330–£550 in labour alone. Beyond that, buy panels and posts together from a timber merchant rather than a big-box DIY store — trade yards are typically 15–25% cheaper on bulk orders. Ordering more than 10 panels usually qualifies for free delivery too, saving another £30–£60.

If you need to fence on a tight budget, lap panels at £20–£25 each are the cheapest option that still gives full privacy. Pair them with concrete gravel boards (£8–£12 each) and the panels will last much longer, even though the gravel boards cost more upfront than timber ones.

5 Common Fencing Mistakes (and How to Avoid Them)

I see the same mistakes on fencing jobs year after year. Every one of them costs money to fix, and most of them are completely avoidable if you know what to watch for.

1. Setting Posts Too Shallow

The minimum post depth is 600mm underground. I regularly see DIY fences with posts buried only 300–400mm deep, and these are the ones that blow over in the first autumn gale. A 1.83m fence panel acts like a 3.3 square metre sail in the wind — the leverage on a shallow post is enormous. For exposed gardens or fence runs over 1.5m high, I go to 750mm deep every time. The extra 15 minutes of digging per post is nothing compared to rebuilding a flattened fence.

2. Not Using Gravel Boards

Fence panels sitting directly on soil will start rotting from the bottom within 2–3 years. The bottom rail and lowest slats absorb moisture from the ground, and once rot starts, it spreads upwards. A 150mm gravel board costs £4–£7 for timber or £8–£12 for concrete — far cheaper than replacing a £30–£55 panel. Concrete gravel boards are the better investment because they never rot and never need replacing.

3. Forgetting About Boundary Ownership

Before you build anything, check your title deeds to confirm which boundaries you own. The common "T" mark on the plan indicates ownership — the "T" points into the property of the owner responsible for that boundary. Building a fence on your neighbour's boundary without agreement is a fast route to a dispute. If you are unsure, talk to your neighbour first. A 5-minute conversation saves months of arguments.

4. Using the Wrong Post Length

For a 1.83m (6ft) fence with a 150mm gravel board, you need the post to extend 1.98m above ground (1.83m panel + 0.15m gravel board), plus at least 600mm underground. That means a total post length of 2.58m — so you need to buy 2.7m (9ft) posts, not 2.4m (8ft). I have seen people buy standard 2.4m posts for this setup and end up with the panel sticking above the post, which looks terrible and weakens the fence. Always calculate: panel height + gravel board height + underground depth = minimum post length.

5. Not Checking for Underground Services

Before digging any post holes, check for underground pipes and cables. Water mains, gas pipes, drainage and electricity cables can all run through garden boundaries. In the UK, you can request a free underground services map from your local authority or use a cable avoidance tool (CAT scanner), which you can hire for around £25–£40 per day. Hitting a gas pipe or electricity cable is dangerous and expensive — a moment of checking prevents a serious problem.

How Many Fence Boards Do I Need Per Metre?

If you are building a closeboard or feather edge fence from individual boards rather than pre-made panels, you need to calculate the number of boards per metre based on the board width and the overlap.

Featherboard Calculation

Standard feather edge boards are 100mm (4 inches) or 125mm (5 inches) wide. They overlap each other by 25mm to shed water and prevent gaps. So the effective coverage per board is:

• 100mm boards with 25mm overlap: 75mm effective width → 14 boards per metre
• 125mm boards with 25mm overlap: 100mm effective width → 10 boards per metre
• 150mm boards with 25mm overlap: 125mm effective width → 8 boards per metre

Boards Per Fence Run

Tip: Always add 10% extra for waste, splits and cuts around corners. Feather edge boards cost £1–£2 each, so a 10-metre closeboard fence using 125mm boards costs around £100–£200 for boards alone, plus posts, rails, gravel boards and fixings.

Closeboard vs Panel Fencing — Which Is Cheaper?

Pre-made closeboard panels (£35–£55 each) are quicker to install but more expensive than building from individual boards. For a 10-metre fence:

• Pre-made panels: 6 panels × £45 = £270 for panels alone
• Individual boards: 100 boards × £1.50 + 3 arris rails per bay × £5 = £240

The real advantage of individual boards is that you can replace a single damaged board for £1.50 instead of replacing an entire £45 panel. Over 10 years, closeboard built from individual boards works out significantly cheaper to maintain.

Fencing Cost Per Metre UK — 2026 Price Breakdown

Here is what a garden fence costs per running metre in 2026, with materials only. These prices assume standard 1.83m (6ft) high fencing with timber posts, Postcrete, gravel boards and post caps included.

Budget benchmark: For a typical 20-metre rear garden fence (approximately 11 panels), expect to pay £500–£750 in materials for DIY installation, or £900–£1,400 fully installed by a fencing contractor. Getting three quotes is always worth it — prices vary significantly between contractors even in the same area.

More Fencing Questions Answered

Best Fencing Products UK 2026 — Our Top Picks

These are the most popular fencing products available in the UK right now — from budget lap panels to heavy-duty closeboard. We've included the essential accessories too.

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

Where to Buy Fencing in the UK

Once you know how many panels and posts you need, compare prices across these suppliers. Buying panels, posts and Postcrete together often qualifies for bulk pricing or free delivery.

Links marked above are affiliate links — we may earn a small commission at no extra cost to you. We only link to reputable UK suppliers.