Estimate fence materials — posts, rail sections, and pickets — from your fence length, post spacing, and picket width.
posts = ceil(length ÷ spacing) + 1; pickets = length_in ÷ (picket_w + gap)
Posts are spaced 6–8 ft apart with one extra at the end. Pickets are counted by fence length divided by picket width plus gap.
Use the concrete calculator to estimate bags for setting each post.
For a 100 ft fence with posts every 8 ft: 100 ÷ 8 = 12.5, rounded up to 13 sections, needing 14 posts (one extra for the final end). With 2 rails per section that's 26 rails. For pickets at 5.5 inches wide with a 0.25-inch gap: 100 ft is 1,200 inches, divided by 5.75 inches per picket = about 209 pickets.
Each post should be set in concrete — figure one to two 50 lb bags of concrete per post depending on post and hole size, so 14 posts is roughly 20-28 bags. Use the concrete calculator to confirm based on your hole dimensions.
Counts are geometric. Picket width and gap vary by style — a standard dog-ear picket is 5.5″ wide.
A fence estimate is three counts off the total length. Posts repeat at the chosen spacing (usually 6 to 8 feet), with extra posts at every corner, end, and gate. Rails run between posts — two for a short or picket fence, three for a tall privacy fence to keep boards from warping. Pickets are the fence length divided by the picket width plus the gap, rounded up.
Each post is set in concrete: hole depth about a third of the above-ground height (deeper below the frost line), taking one to two bags per hole. Multiply by the post count. Gates are estimated separately — heavier gate posts, a frame or kit, hinges, a latch, and a drop rod for double gates — and you subtract the gate opening from the picket run.
Typically 6 to 8 feet on center for wood fences.
Typically 6 to 8 feet on center for wood fences, closer for tall privacy fences or windy sites where panels catch wind like a sail.
About one to two 50-60 lb bags per post for a standard 4×4 in a 10-inch-wide hole. Deeper or wider holes need more.
Divide the fence length in inches by the picket width plus the gap between pickets, then round up. For example, 5.5-inch pickets with a 0.5-inch gap consume 6 inches each.