How do I calculate fence picket spacing?
Find a whole picket count and the actual gap for a straight run.
Short answer
Measure the usable picket field, enter the real picket width and maximum gap, then let the count round up before reviewing the actual gap.
For homeowners laying out an even picket field between posts or other fixed points.
How to do it
Measure the usable run
Leave out posts, gate openings, and end setbacks so the run is the space the pickets will fill.
Enter picket details
Use the actual picket width and the largest gap you want to allow.
Review the whole count
The tool rounds to a whole picket count and recalculates the gap from that count.
Check the field
Confirm the result against your post, rail, gate, slope, and fence-system layout.
Formula
Picket count is rounded up from run length, picket width, and maximum gap. Actual gap is recalculated from the resulting count.
Illustrative example
A 96 inch run with 3.5 inch pickets and a 2 inch maximum gap produces 18 pickets and an actual gap of about 1.94 inches.
Common mistakes
- Including post width in the picket run
- Using nominal instead of actual picket width
- Forgetting gates or end setbacks
Before you buy
Confirm picket width, rails, posts, caps, gates, and any local gap requirement before ordering a full run.
What this guide does not cover
This is a straight-run spacing estimate. It does not lay out posts, rails, caps, gates, slopes, or decorative patterns.
Use the calculator
Fence Picket Spacing Calculator is the primary tool for this guide. You can also browse the other fencing calculators.