Fence Calculator
Find how many posts, rails and pickets a wood fence needs from its length, height and picket spacing.
Change the values and press Calculate to work out your own figures.
Enter the fence's length and height and the picket size and gap.
Show the working
- posts = ⌈length ÷ post spacing⌉ + 1
- rails = sections × rails per section
- pickets = length ÷ (picket width + gap), rounded up
How to use it
Enter the fence's length and height and the picket size and gap.
Lengths can be decimals, fractions or tape entries such as 12' 6 1/2" (in feet or inches). Prices are optional.
Key facts
posts = ⌈length ÷ post spacing⌉ + 1 rails = (posts − 1) × rails per section pickets = length ÷ (picket width + gap), rounded up
Posts
Set about a third of the fence's height in the ground (a 6 ft fence on 8 ft posts, 2 ft deep), below the frost line. Wood posts go every 6–8 ft.
Questions
How many posts for a 100 ft fence?
14 posts at 8 ft spacing.
How many pickets for 100 ft?
160 pickets of 5.5 in with 2 in gaps.
Formulas
posts = ⌈length ÷ post spacing⌉ + 1 rails = (posts − 1) × rails per section pickets = length ÷ (picket width + gap), rounded up
Sources
Limitations
- Material densities are typical values (the midpoint of the commonly published range); real loads vary with moisture, grading and compaction, so check with your supplier or type in their density.
- Tank results are the geometric volume; real tanks have wall thickness and fittings.