Fence Calculator
Posts, panels, rails, pickets and post-hole concrete for a fence with gates.
About this tool
Enter the total fence length, the post spacing or panel width, the number of separate straight runs, and the number and width of gates. For a picket or close-board fence, enter the board width and gap. For ready-made panels, leave the board width at zero. Add the post size and hole size to estimate concrete, and the yield of one bag to count bags.
How fence materials are counted
Each straight run needs one more post than it has sections, because there is a post at both ends. Each gate takes its width out of the fenced length and adds a post. A 30 m panel fence with one 0.9 m gate leaves 29.1 m to fill. With 1.83 m (6 ft) panels that is 16 panels and 18 posts. For a picket fence, divide the fenced length by the board width plus the gap. A 100 ft run with a 3.5 ft gate, 8 ft post spacing and 3.5 in pickets with half-inch gaps needs 13 sections, 15 posts, 39 rails and 293 pickets. Post-hole concrete is the volume of each hole minus the post. A common rule is a hole three times the post's width, with a third of the post's length in the ground. Count each side of a corner as its own run. Honest limits: check boundary lines and local rules on fence height before you build, and allow extra boards for defects. The concrete calculator sizes larger footings, the board foot calculator prices timber by volume and the paint calculator estimates stain or paint.
Frequently asked questions
How many fence posts do I need?
For one straight run, the number of sections plus one, plus one more for each gate. A 30 m run of 1.83 m panels with one gate needs 18 posts.
How far apart should fence posts be?
Usually 1.83 m (6 ft) for UK panels and 6โ8 ft in the US. Closer spacing makes a stronger fence.
How much concrete per fence post?
The hole's volume minus the post. A 300 mm hole, 600 mm deep, around a 100 mm post takes about 0.036 mยณ.
Is my data saved?
No. The calculation runs in your browser and nothing is stored or sent.