Measure the fence run
Enter the total fence length in feet, including sections where gates will be installed.
Free woodworking tool
Free Fence Calculator
A fence calculator estimates how many panels, posts, rails, pickets, concrete bags, and gates a fence project needs. Use this free fence material calculator to turn a fence length, panel width, post spacing, and local prices into a practical shopping estimate.
Fence inputs
Local prices
Material estimate
15 fence panels, 18 posts, 36 concrete bags, and 1 gate estimated for a 120 ft fence.
Fence panels
15
8 ft prefab panels
Line and gate posts
18
16 line posts, 2 gate posts
Rails
45
3 rails per section
Pickets
281
10% waste included
Concrete bags
36
2 bags per post
Gates
1
4 ft each
Prefab panels
$1,767
Panels, posts, concrete, and gates.
Rails and pickets
$1,729.85
Rails, pickets, posts, concrete, and gates.
Prefab panel estimate: $1,767 for panels, posts, concrete, and gates.
Stick-build estimate: $1,729.85 for 45 rails, 281 pickets, posts, concrete, and gates.
Adds 10% picket waste for cuts, sorting, damage, and board selection.
Gate openings use 2 dedicated gate posts and 4 ft per gate.
How to use this fence calculator
Set panel and post spacing
Choose the panel width or section length and the maximum post spacing you plan to use.
Add gates and waste
Enter gate count, gate width, and a waste percentage for cut pickets, damaged boards, and layout mistakes.
Enter local material prices
Add prices for panels, posts, rails, pickets, concrete bags, and gates to compare prefab and stick-built costs.
Review the material list
Use the panel, post, rail, picket, concrete, gate, and cost totals as a planning checklist before buying materials.
Fence calculator FAQ
How do I calculate how many fence panels I need?
Subtract gate openings from the total fence length, divide the remaining run by the panel width, and round up. For an 8-foot panel, 116 feet of net fence needs 15 panels.
How many fence posts do I need?
Divide the net fence run by the post spacing, round up, then add one end post. Add two extra gate posts for each gate opening.
How much concrete do fence posts need?
A quick planning estimate is one to two 50-pound bags per line post for small fences. Tall fences, soft soil, frost depth, and larger post holes may require more.
Should I use prefab fence panels or build with rails and pickets?
Prefab panels are faster to install and easier to price. Rails and pickets give you more layout control, help on slopes, and can be cheaper when local lumber prices are favorable.
How much waste should I add for a wood fence?
Use about 10% waste for a simple straight fence. Increase to 12% to 15% for slopes, many corners, custom picket spacing, or boards that need sorting.
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