Fence Calculator
Type each straight run on its own row and the takeoff follows underneath: a 24 ft run of 8 ft panels is 3 panels on 4 posts, and 72 pickets at 3.5 in with a 0.5 in gap. The two things that actually move the order are both fields here rather than assumptions. A gate is one: a 4 ft opening on that same 24 ft run leaves 20 ft of fencing, so it is still 3 panels but 5 posts, because the fencing stops at a post on one side of the opening and starts again at a post on the other. The corner is the other: two 24 ft runs that meet are 6 panels and 7 posts, not 8, because the post at the corner belongs to both runs. Every run is rounded up to whole panels on its own, so a 6 ft run is 1 panel and 2 posts, and the page names the width the last panel is cut to instead of hiding it in a total. Panels, posts, pickets and cost stay separate numbers, with your own prices, so a quote that looks wrong can be checked line by line.
Run 1 24 ft
panel 8 ft
gates 0
panels 3
posts 4
pickets 72One row for each straight length. A fence that turns a corner is two rows, because two straight lengths are something you can check with a tape, and the post where they meet is then counted once.
- Panels are whole: a run that is not a whole number of panels rounds up, and the last panel is cut to fit. Every run here divides into whole panels.
- A straight run of panels stands on one more post than it has panels, because a post carries the end of one panel and the start of the next.
- One run, so there is no corner post to share. Add a second run and the post where they meet is counted once.
- No gate openings. Add one and its width comes out of the run it sits on, with a post added at the opening.
- Pickets are counted across the fenced length on a 4 in pitch, 3.5 in of board and 0.5 in of gap, so a part panel takes only the boards it needs.
- This counts material for the lengths you typed. It makes no structural, load or code recommendation.
Common questions
- How many posts does a fence run need?
- One more than it has panels. A post carries the end of one panel and the start of the next, so a straight run of 3 panels stands on 4 posts, a run of 13 panels on 14, and a single 6 ft run of one cut panel on 2. Two things change that arithmetic, and both are handled here. A gate opening adds one post to its run, because the fencing stops at a post on one side of the opening and starts again at a post on the other: a 24 ft run with a 4 ft gate is 3 panels and 5 posts. Where two runs meet, the post at the corner belongs to both, so two 24 ft runs are 7 posts rather than 8, and a closed perimeter of 50, 30, 50 and 30 ft comes to 22 panels standing on 22 posts.
- How many panels do I need for 100 feet of fence?
- With 8 ft panels, 100 ft is 12.5 panels, so 13 panels and 14 posts, and the page tells you the last panel is cut to 4 ft. With 6 ft panels it is 16.67, so 17 panels and 18 posts, with the last one cut to 4 ft again. Rounding happens on each run separately rather than on the total, which is the part a single-length calculator gets wrong: two 6 ft runs are two whole panels, not one and a half. If you are setting posts at a spacing rather than buying prefab panels, type that spacing into the panel width field: the arithmetic is the same, and the panel count is then the number of bays between posts.
- How do gate openings change the material count?
- The opening comes out of the fencing on the run it sits on before any panel is counted, and it adds one post. On a 24 ft run, a 4 ft gate leaves 20 ft to fence, which is 3 panels with the last cut to 4 ft, 5 posts and 60 pickets rather than 72. Gates are rows of their own, each with its own width and the run it belongs to, so a 4 ft walk gate and a 10 ft double gate can sit on the same fence. A run that is nothing but an opening is allowed: a 4 ft run with a 4 ft gate comes back as 0 panels and 2 posts, which is what a gate hung between two posts actually needs.
- How many pickets are in a fence, and how is the pitch worked out?
- Pickets are counted across the fenced length on the pitch you set, which is the board width plus the gap: a 3.5 in picket with a 0.5 in gap is a 4 in pitch, so 24 ft of fencing takes 72 pickets and 20 ft takes 60. The count is floor((fenced length + gap) / pitch), so the last board sits against the end with no gap after it. Pickets follow the fencing rather than the panel count, which is why a 6 ft run takes 18 boards rather than a whole panel's 24. Leave the picket width empty and pickets are left out altogether: panels and pickets are two ways of building the same run, so price one or the other, and the page says so when both prices are filled in.
- What does this calculator not do?
- It counts material for the lengths you type and stops there. It makes no structural, load or code recommendation: it will not tell you how a post is held in the ground, what the fence has to stand against, or what the rules are where you live. Those are decisions with a structure or a rulebook behind them and they belong with your supplier or your local authority. There is no price list either. The cost is your own price per panel, post, picket and gate multiplied by the counts above, with no delivery, offcuts or fixings in it, because those are local and they move.
- Is anything uploaded, and does it cost anything?
- No. The arithmetic runs in your browser, there is no account and nothing is sent anywhere. Your runs, the panel width, the gates, the picket figures and the units are kept in your browser's own storage so the page opens where you left it, and clearing your browser data clears that too. The four price fields are never saved. The tool is free to use, and the core of it is never gated.
Exact arithmetic on the lengths you enter. It counts material for a straight run and shares corner posts; it makes no structural, load or code recommendation.