Fence Picket Calculator
Count pickets for a wood fence. Enter fence length in feet, picket width and gap in inches, and a waste percentage to get the pickets to buy — plus posts at 8 ft spacing and 2x4 rails to go with them.
Example: with Fence length (ft) 100 · Picket width (in) 5.5 · Gap between pickets (in) 0 · Waste factor (%) 5 → Pickets to buy: 230 pickets (waste included).
- Pickets (exact)219 pickets exact
- Posts14 posts at 8 ft spacing
- Rails39 rails (3 per section, 6 ft privacy)
Computed by the calculator below using its default values. Change any input to see your own numbers.
Pickets = fence length ÷ (picket width + gap). A standard dog-ear picket is a 1x6, which actually measures 5-1/2 in wide.
The picket math, honestly
Each picket plus its gap occupies one repeating unit along the fence, so the count is fence length in inches divided by (picket width + gap). A privacy fence butts pickets tight (zero gap); spaced picket fences typically leave 1-1/2 to 2-1/2 in. Watch the widths: lumber names are nominal, so a "1x6" picket is really 5-1/2 in and a "1x4" is 3-1/2 in.
The waste factor covers culls — warped, split, or wane-edged boards you will reject from the stack — plus the cut pickets where the run ends or steps on a slope. Five percent is normal for decent pre-cut pickets; rough-sawn bundles deserve 10%.
Posts and rails to match
Posts here are laid out at the standard 8 ft on center: sections = length ÷ 8 rounded up, posts = sections + 1. Gates add a post per side. Rails are counted at 3 per section, the right call for a 6 ft privacy fence (top, middle, bottom); a 4 ft fence can drop to 2 per section — subtract one section count from the rail total if that is your build. Corners and slope steps add posts the calculator cannot see, so walk the line before ordering.
How it’s calculated
Pickets (exact) = fence length × 12 ÷ (picket width + gap), rounded up; pickets to buy = exact × (1 + waste%/100), rounded up. Sections = length ÷ 8 ft, rounded up; posts = sections + 1; rails = sections × 3 (6 ft privacy standard). Nominal picket widths: 1x6 = 5.5 in actual, 1x4 = 3.5 in actual.
Assumes one straight run with a picket at each end — corners, gates, and grade steps each add a post and change the last picket in that section.
Pickets per 8 ft section (butted tight)
| Picket | Actual width | Per 8 ft section |
|---|---|---|
| 1x4 | 3.5 in | 28 |
| 1x6 (standard dog-ear) | 5.5 in | 18 |
| 1x8 | 7.25 in | 14 |
Computed as 96 in ÷ actual width, rounded up; nominal-to-actual widths per US softwood lumber standard (PS 20).
Common mistakes
- Using nominal width in the math — a 1x6 picket is 5.5 in, and pretending it is 6 in shorts a 100 ft fence by about 20 pickets.
- Forgetting the gap dries wider: green treated pickets shrink 1/4 in or so as they dry, so tight-butted fences develop gaps and spaced fences grow theirs.
- Counting posts as length ÷ 8 without the +1 — a 100 ft run needs 14 posts, not 13 (and gates add more).
- Skipping waste on bundle-grade pickets; expect to cull several warped boards per hundred.
Frequently asked questions
How do I calculate fence pickets?
Pickets = fence length in inches ÷ (picket width + gap between pickets), then add waste. A 100 ft privacy fence with 5.5 in pickets butted tight needs 219 pickets exact, about 230 with 5% waste.
How many pickets per 8 foot section?
With standard 5.5 in dog-ear pickets butted tight, 18 per 8 ft section (96 ÷ 5.5 = 17.5, rounded up). With a 1.5 in gap it drops to 14.
What gap should I leave between pickets?
Zero for privacy, 1.5 to 2.5 in for a spaced picket look. If you install green pressure-treated pickets tight, expect roughly 1/4 in gaps to open as they dry — some builders count on it.
How many posts and rails do I need?
At 8 ft spacing: posts = (length ÷ 8, rounded up) + 1, and rails = 3 per section for a 6 ft privacy fence or 2 per section for 4 ft. A 100 ft run is 13 sections: 14 posts and 39 rails.
Does the calculator handle slopes and corners?
Corners just split the run — calculate each straight leg separately and share the corner post. Slopes racked parallel to grade use the same picket count; stepped fences waste more pickets to angle cuts, so raise the waste factor.