How Many Fence Posts Do I Need?
Post count is fence length ÷ post spacing, plus one — then add posts for corners, ends and gates. A 100 ft fence at 8 ft spacing needs 14 line posts. Use the Fence Post Calculator for your exact run.
Ready to run the numbers? Use our Fence Post Calculator or the Fence Calculator to get an instant material estimate.
Spacing rules
Standard post spacing is 8 ft center-to-center for most wood fences. Drop to 6 ft in high-wind areas or for 8 ft tall fences so the rails stay stiff. Wider spacing saves posts but makes the fence more likely to sag between posts.
The post-count formula
Divide the total fence length by the post spacing to get the number of sections, then add one for the final post. This gives a straight run with no openings. Round the section count up so the last section is not longer than the spacing.
Source: Sections = length ÷ spacing; posts = sections + 1. Add posts for corners, ends and gates.
A 100 ft fence at 8 ft spacing: 100 ÷ 8 = 12.5 → 13 sections → 14 line posts. Add 2 posts for a gate and 1 for each corner.
Add corners, ends and gates
- Add one post at each corner where the fence changes direction.
- Add one post at each end where the run stops (against a house or wall).
- Each gate needs two sturdy gate posts — usually 6×6, set in concrete.
- Use 4×4 posts for fences up to 6 ft; step up to 6×6 for heavy or 8 ft fences.
Buying and setting tips
- Buy pressure-treated posts rated for ground contact.
- Set posts in concrete — about two 80-lb bags per 4×4 post (see the Post Hole Concrete Calculator).
- Call 811 to mark underground utilities before you dig — it is free and required in most areas.
- Let concrete cure 24–48 hours before attaching rails or pickets.
Frequently asked questions
How many fence posts do I need for 100 feet?
At 8 ft spacing, 100 ft of fence has about 13 sections and needs 14 line posts. Add one post for each corner, end and gate opening.
How far apart should fence posts be?
8 ft center-to-center is standard for most wood fences. Use 6 ft spacing in high-wind areas or for 8 ft tall fences so the rails stay stiff.
How many posts do I need for a gate?
Each gate needs two sturdy gate posts, usually 6×6, set in concrete. Add these to the line-post count from the calculator.
Calculators for this guide
Put these numbers to work with the free calculators referenced above.