Fence picket quantity

What this calculation does

A picket estimate repeats one equal-gap layout across measured clear bays and reports both the count and the gap that layout produces.

Measure the clear width of one typical bay, count equal bays, measure a picket, and enter the maximum gap you chose.

Enter the measurements

1. Clear width of each bay: Measure between the inside faces defining one clear bay.
2. Number of equal bays: Count only bays with the same clear width.
3. Measured picket width: Measure the actual picket face width.
4. Chosen maximum gap: Enter the project-selected maximum gap.

Formula and variables

Pickets per bay = ceil((clear bay width + chosen maximum gap) ÷ (picket width + chosen maximum gap)). Resulting gap = (clear bay width − picket count × picket width) ÷ (picket count − 1), or zero for one exact-width picket. Total = pickets per bay × bay count.

The per-bay count rounds up from the chosen maximum gap. The resulting equal gap is then derived from the remaining clear width.

Read the result

Twelve pickets fit each 70 in bay with about 0.364 in between them, for 120 pickets across ten bays.

Worked example

Inputs: Ten 70 in clear bays, 5.5 in pickets and a 0.5 in maximum gap

1. Pickets per bay = ceil((70+0.5)÷(5.5+0.5)) = 12.
2. Gap = (70−12×5.5)÷11 = 4÷11 ≈ 0.364 in; total = 12×10 = 120.

Expected result: 12 pickets per bay, 120 total and about 0.364 in resulting gap