How Many Fence Posts Do I Need?
The quick formula, post count tables by fence length, and what to add for gates.
The number of fence posts you need depends on two things: your total fence length and the spacing between posts. The basic formula is straightforward: divide your fence length by the post spacing, round up, then add 1. For example, a 100-foot fence with 8-foot post spacing needs ceil(100 ÷ 8) + 1 = 13 + 1 = 14 posts.
The Fence Post Formula
Step by step:
- Measure your total fence length in feet.
- Decide on post spacing — typically 6, 8, or 10 feet.
- Divide fence length by post spacing and round down to the nearest whole number.
- Add 1 for the final end post.
- Add 2 extra posts for each gate opening.
Corner posts: Corner posts are automatically included in this formula — you do not need to add extra posts for corners. The formula accounts for the end post of each run, which doubles as the corner post when runs meet at a 90° angle.
Fence Post Count Table
Use this table to look up your post count by fence length and spacing. These numbers do not include gate posts — add 2 per gate opening.
| Fence Length | 6-ft spacing | 8-ft spacing | 10-ft spacing |
|---|---|---|---|
| 50 ft | 10 | 8 | 6 |
| 75 ft | 14 | 11 | 9 |
| 100 ft | 18 | 14 | 11 |
| 150 ft | 26 | 20 | 16 |
| 200 ft | 35 | 26 | 21 |
| 300 ft | 51 | 39 | 31 |
| 400 ft | 68 | 51 | 41 |
Gate posts not included. Add 2 posts per gate opening.
What Post Spacing Should You Use?
Post spacing affects both cost and fence strength. Here's how to choose:
- 6-foot spacing: Best for tall privacy fences (8 ft), heavy board-on-board construction, and areas with high wind load. More posts = stronger fence, higher material cost.
- 8-foot spacing: The standard for most residential wood fences — picket, privacy (6 ft), and board-on-board. Balances strength and cost. Works with standard 8-foot 2×4 rails without sagging.
- 10-foot spacing: Suitable for split rail fences and chain link. Too wide for most wood privacy fences — rails will sag.
As a rule of thumb: the taller and heavier your fence, the closer your posts should be. When in doubt, use 8 feet.
Don't Forget Gate Posts
Every gate opening requires 2 dedicated gate posts — one on each side. These are in addition to the line posts calculated by the formula above.
- 1 single gate: Add 2 posts
- 2 single gates: Add 4 posts
- 1 double gate: Add 2 posts (one on each end; the center may share a post)
Gate posts carry extra stress from the gate's weight and swinging motion. Use 4×4 or 4×6 posts for gate openings and always set them in concrete, regardless of your line post installation method.
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Frequently Asked Questions
How many fence posts do I need for 100 feet?
For a 100-foot fence with 8-foot post spacing, you need 14 posts: ceil(100 ÷ 8) + 1 = 13 + 1 = 14. Add 2 extra posts per gate opening.
How far apart should fence posts be?
Standard spacing is 8 feet for most wood privacy and picket fences. Use 6 feet for heavier 8-foot-tall fences or in areas with high winds. Split rail fences use 8–10 feet.
Do corner posts count as extra posts?
No. Corner posts are already counted in the formula. Each run is calculated separately, and the end post of one run is the same post as the start of the next — you do not add extra posts at corners.
How many posts for a 200-foot fence?
A 200-foot fence with 8-foot post spacing needs 26 posts. With 6-foot spacing, you need 35 posts. Use the table above for other spacing combinations.
How many posts do I need for a fence with 2 gates?
Add 4 extra posts (2 per gate) to your baseline count. For a 100-foot fence with 8-foot spacing and 2 gates: 14 baseline + 4 gate posts = 18 posts total.