How Many Fence Panels Do I Need? (With Worked Example)

Step 1: Measure the full length of your fence line

Run a tape measure along the line where the fence will go, from one end to the other. If the fence turns a corner, measure each straight section separately and write them down. Measure in metres — it makes the maths easier — and round up to the nearest 10cm rather than down.

It's worth knocking a peg in at each end and stretching a string line between them. That shows you exactly where the posts will sit, and you'll spot anything in the way, such as tree roots, drain covers or an old concrete footing.

Step 2: Work out how many panels

Standard UK fence panels are 6ft wide, which is about 1.83m. Concrete posts add a little width between panels too, but for planning purposes 1.83m per panel is close enough.

The sum is simple:

Panels = fence length (m) ÷ 1.83, rounded up to the next whole panel.

If the last panel only needs to cover a short gap, you can usually trim a timber panel to fit. Featheredge panels are easier to cut down than lap panels because the boards are fixed to a rail on the back. Browse our fence panels or go straight to featheredge panels.

Step 3: Work out how many posts

On a single straight run, every panel sits between two posts, so you always need one more post than panels:

Posts = panels + 1

For every extra corner, add one more post. If you're fencing three sides of a garden, treat each side as its own run and add them up.

With slotted concrete posts, there are three types: intermediate posts (slots on both sides), end posts (slot on one side, used where the fence stops) and corner posts (slots at right angles). Timber posts work for any position because you fix panels to them with brackets or screws.

Which post length?

Roughly a quarter of the post should be in the ground. For a 6ft (1.83m) panel on top of a gravel board, a 9ft post is the usual choice. For a 5ft panel with a gravel board, an 8ft post is normally right. Our fence panel sizes guide covers every height.

Step 4: Gravel boards

A gravel board sits at the bottom of each bay, between the posts, and keeps the timber panel off the soil so it stays drier for longer. You need one gravel board per panel. Concrete gravel boards slot straight into concrete posts. See our range of gravel boards.

Step 5: Post mix

Most people set posts in rapid-setting post mix rather than mixing concrete by hand. As a rough guide, allow about two 20kg bags per post. Large holes, soft ground or longer posts may need more, so it's sensible to order a bag or two spare. Always check the instructions on the bag. You'll find it in our post mix range.

Worked example: a 20m straight fence

Say your back fence runs 20m in a straight line, and you want 6ft high featheredge panels on concrete posts with gravel boards.

If the same fence turned a corner halfway along, you would swap one intermediate post for a corner post and treat each side as its own run.

A quicker option: bay packages

One panel, one post and one gravel board make up a single "bay" of fence. Our fence bay packages bundle those together so you can simply order the number of bays you need, then add one extra post to finish the run. You'll find them on the homepage.

Common mistakes to avoid

• Rounding the panel count down and coming up short at the end.
• Forgetting the extra post at the end of the run.
• Ordering intermediate posts only, with no end or corner posts.
• Choosing posts that are too short once the gravel board is added.
• Not checking access — panels are 1.83m long and need to be carried through to the garden.

Once you know what you need, add it to your basket and choose delivery or free Click & Collect. Delivery details are on our delivery page.