How many fence pickets do I need for a given fence length?

Divide the fence length by the pitch — picket width plus the gap between pickets — and round up. For example, a 20m run using 100mm pickets with a 40mm gap has a pitch of 140mm, giving roughly 143 pickets before any waste allowance is added.

Does a wider gap between pickets mean I need fewer pickets?

Yes. A wider gap increases the pitch (picket width plus gap), so fewer pickets fit — and are needed — across the same fence length. A solid privacy fence with no gap needs the most pickets per metre; a semi-open picket fence with a wide gap needs the fewest.

How much do fence pickets cost in the US?

US pickets typically run around $3-$6 each depending on wood type (pressure-treated pine vs. cedar) and width, so the 150-picket example above comes to roughly $450-$900 in material cost alone.

Fence Picket Calculator — How Many Pickets Do You Need | Construction Calculators

Fence Picket Calculator: How Many Pickets Do You Need

Ordering too few fence pickets means a stalled job and a return trip to the timber yard; ordering too many wastes money on pickets you'll never use. This calculator works out exactly how many pickets a fence run needs from just two numbers — the width of the picket you're using and the gap you want between them — plus a waste allowance for cuts and breakages. Enter your fence length, picket width and gap spacing, and read off the total picket count and material cost immediately.

How to use the fence picket calculator

Enter the total fence run length you're covering.
Enter the width of a single picket.
Enter the gap you want between pickets — zero for a solid privacy fence, wider for a semi-open picket fence.
Set a waste allowance (5% by default) to cover cuts and breakages.
Read off the total picket count and the estimated material cost.

The formula, with a worked example

Each picket takes up its own width plus the gap that follows it — call that the pitch. Picket count = fence length ÷ pitch, rounded up so the run is never left short by a fraction of a picket.

Worked example: a 20m fence run, 100mm-wide pickets, a 40mm gap, and a 5% waste allowance. Pitch = 100 + 40 = 140mm, so the raw picket count = 20,000 ÷ 140 ≈ 142.9. Adding 5% waste and rounding up gives 150 pickets for the full run.

Tips and common mistakes

Narrower gaps use more pickets, not fewer. A tighter gap shrinks the pitch, so it fits into the run more times — a solid privacy fence (0 gap) always needs more pickets per metre than an open picket fence with a wide gap. Check the total against your budget before committing to a spacing.

Don't skip the waste allowance. Pickets split when nailed near the end and corner sections rarely use a whole picket, so a 5-10% buffer avoids a second trip to the yard.

At a typical US retail price of around $4 per cedar or pressure-treated picket, the 150-picket worked example above would cost roughly $600 in materials before rails, posts, or fasteners.