Fence Calculator
Enter the fence length, post spacing, and picket sizing to get the number of posts, rails, and pickets needed.
Results
- Posts
- 14
- Rails
- 39
- Pickets
- 219
- Sections
- 13
Estimates only. Round up and buy a little extra to account for waste, spills, and breakage.
Planning a privacy or picket fence? Enter the fence length, post spacing, and picket size and this fence calculator returns the full material list: posts, rails, and pickets, so you buy once and avoid mid-project runs to the lumberyard.
Pair the post count with the post hole concrete calculator to get bag counts for setting every post.
Also used as a wood fence calculator, picket fence estimator, and fence material calculator.
How to use the fence calculator
- Enter the fence length in ft.
- Enter the post spacing in ft.
- Enter the rails per section.
- Enter the picket width in in.
- Enter the gap between pickets in in.
- Optionally add a price to estimate the total project cost.
- Read your quantities instantly — no sign-up, and you can print the estimate to take to the supplier.
Worked example
Inputs
- Fence length
- 100 ft
- Post spacing
- 8 ft
- Rails per section
- 3
- Picket width
- 5.5 in
- Gap between pickets
- 0 in
Results
- Posts
- 14
- Rails
- 39
- Pickets
- 219
- Sections
- 13
Using the example values above, the fence calculator returns 14 (posts). Change any field to match your own project and the numbers update instantly.
How many fence pickets do I need?
Convert the fence length to inches and divide by the picket width plus the gap. A 100 ft fence with 5.5 in pickets and no gap takes about 218 pickets; adding a 1/2 in gap drops that to 200.
Posts go at both ends of every section, so sections + 1 = posts. At 8 ft spacing, 100 ft of fence needs 14 posts and, with 3 rails per section, 39 rails.
Choosing post spacing and rails
Eight feet is the standard post spacing because rails come in 8 and 16 ft lengths. Tightening to 6 ft spacing stiffens the fence in high-wind areas.
Use two rails for fences up to 4 ft tall and three rails for 6 ft privacy fences. Set posts at least one-third of their length deep, and below the frost line in cold climates.
Formula
Sections = length ÷ post spacing. Posts = sections + 1. Pickets = (length × 12) ÷ (picket width + gap).
Frequently asked questions
- How far apart should fence posts be?
- Space posts 6–8 ft on center; closer spacing adds strength in windy areas.
- How many rails per section?
- Use two rails for fences under 5 ft and three rails for taller privacy fences.
- How many pickets for 100 feet of fence?
- About 218 standard 5.5 in pickets with no gap, or 200 with a half-inch gap for airflow.
- How many bags of concrete per fence post?
- Usually 1 to 2 bags of 50 lb mix per post for a 10 in diameter hole at 2 to 3 ft deep. Check the post hole concrete calculator for your exact depth.
Related calculators
Deck Board Calculator
Estimate how many deck boards you need for your deck size.
Board Foot Calculator
Calculate board feet of lumber from thickness, width, length, and quantity.
Fence Cost Calculator
Estimate fence material counts to price out your project.
Square Footage Calculator
Calculate the area of a room or surface in square feet, yards, and meters.