How the fence materials are counted
A fence is a row of sections, and each section sits between two posts. The calculator divides your total length by the post spacing and rounds up to get the number of sections. Posts come to one more than that, since the run needs a post at each end.
Rails are the horizontal boards the pickets attach to, and each section gets two or three. Pickets are counted by dividing the fence length in inches by the picket width plus any gap.
Worked example: 100 feet of 6 ft privacy fence
- 100 ÷ 8 ft spacing = 12.5, so 13 sections
- Posts: 14
- Rails: 13 sections × 3 = 39 rails
- Pickets: 1,200 in ÷ 5.5 = 219 pickets
- Concrete at 2 bags per post: 28 bags
Corners and gates
The count above is for one straight run. For a fence with corners, run the calculator once for each straight side. Where two sides meet at a corner they share a post, so take one post off the total for each corner.
Gates need a solid post on each side. Those posts carry the swinging weight, so set them a little deeper and use extra concrete.
Before you dig
- Call 811. This free US service sends crews to mark buried gas, power and water lines, and many states require it before any digging.
- Confirm the property line. A survey or plat map beats a guess based on where the old fence stood.
- Check local rules. Many towns and HOAs limit fence height and style, and some need a permit.
- Set posts deep enough. A common rule is a third of the post's length in the ground, and below the frost line where winters are cold.
Need the exact concrete volume for wider holes? The concrete calculator has a post hole mode.
Frequently asked questions
How far apart should fence posts be?
Most wood fences put posts 6 to 8 feet apart. Eight feet is common because rails come in 8-foot lengths. Use 6 feet in windy areas or for heavier fence styles.
How deep should fence posts be?
A common rule is one third of the post's total length in the ground, so a 9-foot post holds a 6-foot fence with 3 feet buried. In cold climates, go below the frost line.
How many pickets do I need for an 8 foot section?
With 5.5 inch pickets and no gap, about 18 per 8-foot section. Add space between pickets and the number drops.
How many bags of concrete per fence post?
Two 50 lb bags of fast-setting mix is typical for a 4 by 4 post in a standard hole. Larger holes, 6 by 6 posts and gate posts need more.
Results are estimates for planning. Product coverage, site conditions and installation methods vary, so check manufacturer guidance before you buy.