Fencing Calculator

How many fence panels and posts do I need?

Divide your total run length by the panel width and round up — that's your panel (bay) count. Posts are always one more than panels, because a straight run of, say, five panels needs six posts: one at each end and one between every pair of panels. This tool does that sum for you and rounds every figure up so you're never a panel or a bag short. It assumes a straight run with no gates or corners, so add an extra post for each gate opening and each change of direction.

How many bags of postcrete per fence post?

Most installers use one to two 20kg bags of postcrete (postmix) per post for a standard 6ft fence, depending on post size and hole depth. Heavier or taller posts, or softer ground, push you towards two or more. The calculator defaults to two bags per post so you err on the generous side, but you can change it to match how you actually set your posts. Remember postcrete is a fast-setting product — buy a couple of spare bags rather than running out mid-run.

What size are standard UK fence panels?

The standard UK fence panel is 6ft (1.83m) wide. Heights vary — common heights are 3ft, 4ft, 5ft and 6ft (roughly 0.9m to 1.83m). Because the width is almost always 1.83m, that's the default here, but you can edit the panel width if you're using a non-standard or continental size. Note that the "covered length" the tool shows is your panel count multiplied by the panel width, so if it slightly overshoots your run, the last panel may need trimming to fit.

Building a deck too, or need a full concrete footing?

Fencing off a new deck? Our Decking Calculator works out boards, joists, screws and wastage for the deck itself. If your posts need a proper concrete footing rather than bagged postcrete — for taller fences or exposed sites — our Concrete Calculator has a post-hole mode that works out the volume and mix.

Does this tool store my details?

No. This is a free on-screen calculator — every figure you type stays in your browser and updates live as you go. Nothing is uploaded, saved, sent or shared, and there's no sign-up or download. Close the tab and it's gone.