Fence Picket & Post Calculator
Posts, sections and pickets for a straight fence run.
How it’s calculated
Sections = length ÷ post spacing, rounded up. Posts = sections + 1 (one straight run, no gates). Pickets = length × 12 ÷ (picket width + gap) × (1 + waste%), rounded up.
A nominal “1×6” picket is typically 5.5 in actual width — measure yours. Rails: commonly 2–3 per section; check your design and local code.
Worked examples
100 ft run, 8 ft spacing, 5.5 in pickets, no gap: 12.5 → 13 sections, 14 posts; 1200 ÷ 5.5 = 218.2 → 219 pickets (230 with 5%).
Same run with 2 in gaps: 1200 ÷ 7.5 = 160 pickets (+5% = 168).
Waste factor
5% covers split or warped boards (rule of thumb). Not a single straight run? Calculate each side separately and add the results, then subtract one post for each corner shared by two sides. For a gate, treat the gate opening as a break in the run and make sure there’s a post on each side of it (heavier gate posts are common).
Common mistakes
- Counting shared corner posts twice when you add up several sides.
- Using the nominal picket width (6 in for a 1×6) instead of the actual width (usually 5.5 in).
- Forgetting a post on each side of a gate opening.
FAQ
Corners and gates?
Calculate each straight side separately; shared corner posts are counted once.
How deep do posts go?
Depends on frost line and local code — check your building department.
Shadowbox fences?
Pickets overlap on both sides; calculate each side and add.
Related calculators
- Concrete Bag Calculator: How many 40–90 lb bags of concrete for a slab or pad.
- Mulch & Soil Calculator: Cubic yards and bags of mulch, soil or compost.