Fence Picket Spacing Calculator
Calculate exact picket board counts and uniform spacing gaps between posts for clean shadowbox and picket fence panels.
Picket spacing & gap
Enter your measurements and the result updates as you type.
Overview
Nothing ruins the look of an ornamental or picket fence like uneven gaps between boards or a tiny sliver of wood squished against the post. This calculator balances pickets and gaps mathematically.
Enter your post-to-post bay width, picket board width, and desired spacing to calculate exact board counts and precise uniform gaps down to the fraction of an inch.
Common mistakes
- Using an eyeball estimate for picket spacing that compounds errors, leaving a huge gap at the far post.
- Measuring gap from picket center instead of the clear opening between adjacent board edges.
- Forgetting that wet wood pickets shrink over time, making initial gaps grow wider after summer sun exposure.
- Not cutting a wooden spacer block to match the exact mathematical gap calculated for the bay.
Related calculators
- Fence picket calculator Calculate exactly how many pickets you need from your fence run, picket width and gap, including a waste factor.
- Picket fence calculator Calculate posts, rails and pickets for a classic picket fence with a visible gap between boards, the front-yard style rather than privacy.
- Privacy fence calculator Calculate posts, rails and pickets for a solid privacy fence in any material, with a zero-gap board layout by default.
- Shadowbox fence calculator Calculate materials for a shadowbox fence, which alternates pickets on both sides of the rails for a semi-private, two-sided look.
Related reading
In-depth guides
Frequently asked questions
What is the standard gap between pickets on a front yard fence?
Two to 2.5 inches is standard. It provides visual charm, lets wind pass freely, and prevents pets or small children from squeezing through.
How do you maintain a consistent picket gap during installation?
Cut a wooden scrap block to the exact calculated gap width. Place this spacer block between each picket as you nail or screw boards to the rails.
What is the actual width of a 1x4 and 1x6 fence picket?
Lumber dimensions are nominal. A 1x4 picket actually measures 3.5 inches wide, and a 1x6 picket measures 5.5 inches wide.
How many pickets fit on an 8-foot fence section with a 2-inch gap?
On a 96-inch section using 3.5-inch pickets and roughly 2-inch gaps, you will use 17 pickets with an exact gap of 2.03 inches.
What spacing is required for swimming pool safety picket fences?
Pool safety codes mandate that clear spacing between pickets must not exceed 4 inches, preventing a 4-inch sphere from passing through anywhere.
How does picket spacing work on shadowbox fences?
Shadowbox fences alternate pickets on front and back sides of rails with an intentional overlap (typically 1 to 2 inches) to block direct sightlines.
Should the first picket be tight against the post?
Most builders leave one half-gap or full gap between the post and the first picket for visual symmetry across the whole fence line.
Do pickets expand or contract after installation?
Treated pine pickets shrink across their width as they dry, widening gaps by 1/8 inch or more. Cedar and vinyl remain much more dimensionally stable.