Planning a fence project requires knowing exactly how many posts, rails, and pickets you need before ordering. Getting this wrong costs money and time — this calculator gives you the precise quantities.
Post Count Formula
Posts = (Total Length ÷ Spacing) + 1. For example, a 100 ft fence with 8 ft spacing needs (100÷8)+1 = 13.5, rounded up to 14 posts. Always add 1 for the final end post.
Picket Count Formula
Pickets per foot = 12 ÷ (picket width + gap). A 3.5" picket with no gap uses 12÷3.5 = 3.43 pickets per foot. Multiply by total fence length.
Concrete for Post Holes
Use 2 bags of 80 lb Quikrete per post for standard 6" diameter holes
Hole depth should be 1/3 to 1/2 the post length below grade
6 ft fence: use 8 ft posts (2 ft below grade)
In cold climates, dig below the frost line to prevent heaving
Rail Sizing
Use 2×4 pressure-treated lumber for rails in most climates
2 rails for fences 4 ft and under; 3 rails for 6 ft; 4 rails for 8 ft
Rails run between posts — count spans, not posts
Got your fence quantities?
Build the proposal in BuildQuotes or invoice the job directly.