Fence Calculator

Divide the fence length by the post spacing, round up to get the sections, and add one post — plus one more for each gate. A 100 ft fence with posts 8 ft apart has 13 sections and 14 posts.

Divide the fence length (in inches, less the gates) by the picket width plus the gap. A 100 ft privacy fence with 5 1/2" pickets butted tight needs about 219 pickets; add 10% for culls.

For a 4×4 post in a 10" hole 2 ft deep, about 0.92 cubic feet — a little over one and a half 80 lb bags. The calculator works out the total for your post count, depth and bag size.

A common rule is a third of the fence height, and at least 24", going below the frost line in cold climates. A 6 ft fence usually gets 8 ft posts set 2 ft deep.

8 ft is standard and matches 8 ft rails. Use 6 ft for heavy or tall fences, windy sites, or where the fence has to follow uneven ground.