Fence Calculator
Enter the total length of the fence, its height and the post spacing. The calculator counts 4 × 4 posts, 2 × 4 rails, 5½ in pickets and the fast-setting concrete to set the posts in 10 inch holes.
Add a post for each gate and each corner beyond the ends. Check your property line and call 811 before you dig.
How it’s calculated
- Sections = length ÷ post spacing, rounded up. Posts = sections + 1.
- Rails = sections × 2 (fences up to 4 ft) or × 3 (taller fences).
- Pickets = length (in) ÷ (picket width + gap).
- Post holes are dug a third of the fence height deep (at least 2 ft). Each 50 lb bag of fast-setting mix fills about 0.375 cu ft.
Materials for common fence lengths
Questions
- How many fence posts do I need for 100 feet?
- 14 posts at 8 ft spacing, or 18 at 6 ft spacing, plus one for each gate.
- How many bags of concrete per fence post?
- About 2 to 3 bags of 50 lb fast-setting mix for a 4 × 4 post in a 10 in hole 2 ft deep.
- How deep should fence posts be?
- A third of the post’s height above ground, and at least 2 ft. In cold climates go below the frost line.