Fence Post Spacing Calculator
Bays = run length ÷ the widest spacing allowed, rounded up, and the posts sit at equal centers: a 48 ft run with posts no more than 8 ft apart has 6 equal bays and 7 posts.
Example: replace these measurements
Your post layout
7 posts
7 posts
48 ft measured run
Your shopping list
- 7 posts
Quantities and package details
- End posts
- 2
- Corner posts
- 0
- Gate posts
- 0
- Grade-change posts
- 0
- Line posts
- 5
The calculation
- Fence section: 48 ft horizontal length; 0 ft grade rise; no gate.
- 0 to 48 ft: 6 bays at 8 ft along the slope.
- Horizontal post centers from section start: 0, 8, 16, 24, 32, 40, 48 ft.
Common questions
How do I space fence posts evenly?
Divide the run by your largest allowed spacing, round up to whole bays, then divide the run by that number of bays. A 48-foot run with an 8-foot maximum is 6 bays of 8 feet; a 50-foot run is 7 bays of about 7 feet 1 3/4 inches.
What happens to the spacing at a gate?
Gate posts are fixed, so each side of the gate gets its own equal bays.
How do I space posts on a slope?
Measure the maximum spacing along the slope. Enter the horizontal run and the grade rise, and the calculator works out the slope length.
How to plan the quantity
Enter a straight section between fixed post locations. Its length and gate positions are horizontal measurements between post centers. Use the gate drawing for the distance between gate posts, including the hardware clearances.
Place a gate by entering its first post’s distance from the start and the distance to its second post. The solid fence on either side gets its own equal bays. Add another section at a corner or grade change; choose how its first post connects to the previous end.
A grade rise increases the fence length along the slope. Each section has a constant slope; split it where the grade changes. Post centers are listed horizontally from the start, while the maximum bay spacing is measured along the slope.
Moving a gate redistributes posts on either side. Shared corners and grade-change posts are counted once. The post schedule is geometry, not a recommended span or footing design.
Before you order
- This is layout arithmetic, not a recommended maximum span. Choose the maximum for your fence system, height and site.
- Use a new section for each change of direction or grade. A shared post must be the same physical post on the ground; the first section starts separately.
Before ordering, read the guide: How to measure for a fence: posts, gates, corners and slopes. Or choose another calculator.