Fence Post Calculator
Estimate the number of fence posts needed for a fence run.
Calculation example
Inputs: Fence Length (ft): 100 ft, Post Spacing (ft): 8 ft
Result: 14 posts
A 100 ft fence at 8 ft spacing requires 14 posts.
Formula
Posts needed = ceiling(fence length รท post spacing) + 1.
How to use this calculator
Divide fence length by planned post spacing, round up, then add one post for the starting position.
Before you calculate
Measure the project dimensions as accurately as practical and keep all measurements in compatible units. For material products, use the coverage, yield, density, or package size stated by the manufacturer or supplier rather than a generic assumption.
Choose the waste allowance based on the project shape, installation method, cutting requirements, and material characteristics. A simple rectangular estimate may need adjustment for openings, corners, slopes, joints, patterns, compaction, or other site conditions.
Understanding the result
The calculator provides a planning estimate based on the inputs shown above. It is not a substitute for project drawings, structural design, manufacturer instructions, or local requirements. Before ordering, compare the calculated quantity with the supplier's package sizes and ordering units.
Tips
- Corners, gates and ends can require additional posts.
Frequently asked questions
How are posts estimated?
Fence length is divided by spacing, rounded up, and one starting post is added.
Are extra posts needed?
Corners, ends and gates can require additional posts.
Related calculators
Use compatible units and verify estimates against project specifications, local requirements and manufacturer instructions.