Fence Calculator — Posts, Rails & Pickets
Plan a wood fence before you head to the lumber yard. Enter the fence length, height and spacing to get posts, rails, pickets and concrete bags, with gates included.
Materials
How to estimate fence materials
- Measure the total fence line in feet, including the gate openings.
- Enter how many gates there are and their width, the post spacing (6–8 feet is typical) and the fence height.
- Enter your picket width and spacing. Privacy fences use 0 gap; picket fences often use 2–3 inches. Then read posts, rails, pickets and concrete.
Fence planning basics
Posts are the backbone of a fence. Space them no more than 8 feet apart for wood fences (6 feet in high-wind areas), and set them about one-third of their above-ground height into the ground, below the frost line in cold climates. That is why a 6-foot fence typically uses 8-foot posts. Each gate needs its own pair of sturdy posts.
Rails run horizontally between posts. Fences up to 5 feet usually need 2 rails per section; 6-foot privacy fences need 3 to keep pickets from warping. Pickets are calculated from the fence length minus gate openings, divided by the picket width plus gap, with 5% extra for culls and cuts.
Concrete is estimated for a 10-inch-diameter hole per post, about 0.5 cubic feet each after the post, so roughly one 80 lb bag per post for a 6-foot fence. Before digging, call 811 in the US (or your local utility locating service) to have buried lines marked; it is free and often required.
Need a different tool? Suggest it here — we read every message.
Frequently asked questions
How many posts do I need for a 100 ft fence?
With 8 ft spacing and no gate, 14 posts (13 sections plus one end post). Enter your gates and the calculator places a post on each side of every gate opening.
How deep should fence posts be?
About one-third of the above-ground height, and below the frost line where the ground freezes. A 6 ft fence usually has 2–3 ft in the ground.
How many pickets per 8 ft section?
With 5.5-inch pickets and no gap, about 18. With a 2.5-inch gap, about 12.
Do I need a permit?
Many towns require a permit or limit fence height, especially in front yards. Check with your city or HOA first.