Fence Material Calculator
Plan your fence build — length, post spacing, and picket width turn into posts, pickets, rails, and concrete bags.
This free fence material calculator takes the guesswork out of your lumber order. Enter your fence length, post spacing, picket width, and rails per section, and get exact counts for posts, pickets, rails, and the 50 lb concrete bags for setting the posts.
Standard: 6-8 ft.
5.5" for 1x6 boards. Add your gap to this number to space pickets.
2 for 4-5 ft fences, 3 for 6 ft+.
How to use this calculator
- Step 1: Enter your total fence length in feet.
- Step 2: Set post spacing — 8 ft is standard, 6 ft for windy areas.
- Step 3: Enter picket width in inches (5.5 for 1x6 boards; add your gap if spacing pickets).
- Step 4: Choose rails per section — 2 for shorter fences, 3 for 6 ft and taller.
- Step 5: Click Calculate for posts, pickets, rails, and concrete bags.
The formula
Sections = round up(length / spacing). Posts = sections + 1. Pickets = round up(length x 12 / picket width). Rails = sections x rails per section.
Worked example
A 100 ft fence with 8 ft post spacing, 5.5 in pickets, and 2 rails per section needs 14 posts, 219 pickets, 26 rails, and 14 bags of concrete — 13 sections in total.
Frequently Asked Questions
How far apart should fence posts be?
Eight feet on center is the standard for wood privacy fences, and 6 feet is better in high-wind areas or with heavy board-on-board designs. Wider spacing saves posts but lets rails sag over time. Never exceed 8 feet with standard 2x4 rails — they will bow between posts within a season or two.
How many pickets do I need per foot of fence?
With standard 1x6 pickets (5.5 inches wide) and no gap, you need about 2.2 pickets per foot — roughly 219 pickets for 100 feet. If you want gaps between pickets, add the gap to the picket width before dividing: a 5.5 inch picket with a half-inch gap covers 6 inches, so 200 pickets per 100 feet.
How deep should fence posts be set?
The rule is one-third of the post underground: a 6 ft fence uses 8-9 ft posts with about 2.5-3 ft buried. In cold climates, go below the frost line or frost heave will push posts up over winter. Always set posts in concrete, not packed dirt, and crown the concrete so water drains away from the post.
How much concrete do I need per fence post?
One 50 lb bag per post is the standard estimate for a typical 8-10 inch diameter hole about 2 feet deep. Wider holes or deeper settings in sandy soil may need a bag and a half. This calculator gives you one bag per post, which covers the common case.