Fence Picket Calculator

Fence picket calculator: perimeter ÷ pitch

This fence picket calculator counts pickets for a rectangular, fully fenced yard. The formula is pickets = 2 × (length + width) ÷ pitch, rounded up to a whole picket. Pitch is the space one picket takes up, its width plus one gap, entered in feet in the Spacing field. Cost is pickets × price per picket.

How the count is built

First the calculator finds the perimeter: two lengths plus two widths. A 40 × 30 ft yard has 2 × (40 + 30) = 140 ft of fence. Then it divides the perimeter by the pitch to see how many picket-plus-gap units fit along it. Any fraction is rounded up, so the last gap never comes out wider than planned.

Because the fence closes on itself, the last picket sits next to the first. There is no extra “end” picket to add.

Worked examples

1. Default yard: 40 × 30 ft, 0.5 ft pitch, $3.50 each

• Perimeter: 2 × (40 + 30) = 140 ft
• Pickets: 140 ÷ 0.5 = 280 pickets
• Cost: 280 × $3.50 = $980.00

2. Larger yard: 100 × 50 ft, 5.5 in picket with a 3/4 in gap

• Pitch: 5.5 + 0.75 = 6.25 in ÷ 12 = 0.52 ft (as entered)
• Perimeter: 2 × (100 + 50) = 300 ft
• Pickets: 300 ÷ 0.52 = 576.9, rounded up to 577 pickets
• Cost at $3.50: $2,019.50

Rounding the pitch matters. Entering the exact 0.5208 ft gives 576 pickets; the rounded 0.52 adds one.

Picket pitch reference

Picket width	Gap	Pitch (in)	Spacing field (ft)	Pickets per 100 ft
3.5 in	2.5 in	6.0	0.50	200
5.5 in	0.5 in	6.0	0.50	200
5.5 in	0.75 in	6.25	0.52	193
5.5 in	1.5 in	7.0	0.583	172
3.5 in	0.25 in	3.75	0.3125	320
5.5 in	0 in (tight)	5.5	0.458	219

Yard size	Perimeter	Pickets at 0.5 ft pitch
20 × 30 ft	100 ft	200
40 × 30 ft	140 ft	280
60 × 40 ft	200 ft	400

Wood pickets shrink as they dry. Many builders butt green pickets tightly or leave a small gap and accept that it will widen.

How to measure for pickets

• Measure each side along the fence line, post center to post center.
• Measure one actual picket. A “1 × 6” picket is about 5.5 inches wide.
• Decide the gap. Privacy fences use little or no gap; spaced picket fences often use a gap close to the picket width.
• Subtract the house wall. If the house forms one side, measure only the fenced sides and enter numbers that give that perimeter. For a 40 × 30 ft yard closed by the house on one 40 ft side, the fence is 100 ft, so enter 50 and 0.
• Note gates and corners. Mark each gate width and corner on a sketch. It helps when you split the order between fence panels and gate frames.

Rails, nails, and the rest of the fence

Pickets hang on horizontal rails between posts. A 4 ft picket fence usually uses two rails per section, and a 6 ft privacy fence often uses three. With posts 8 ft apart, a 140 ft perimeter has 18 sections, so two rails per section means 36 rails.

Each picket is usually fastened to each rail with two nails or screws. At 280 pickets and two rails, that is 280 × 2 × 2 = 1,120 fasteners. Use galvanized or stainless fasteners rated for the lumber, since treated wood corrodes plain steel.

Common picket counting mistakes

• Entering pitch in inches. Typing 6 instead of 0.5 gives one-twelfth of the pickets.
• Using nominal picket width. A 6 in board is 5.5 in wide.
• Forgetting post widths. Posts take up a little of each run. On close-spaced pickets, ignoring them adds a few spares.
• No spares. Buy a handful extra for splits and bad boards.
• Mixing up shadowbox counts. Alternating pickets on both sides of the rail needs about twice the pickets of a single layer at the same visual spacing.

Related calculators

Count posts with the fence post calculator, plan a solid fence with the privacy fence calculator, and buy finish with the fence stain calculator.