Fence Calculator
Posts, rails, and pickets for that fence line?
How this is calculated
- Fence span = total length − (gates × 4 ft)
- Sections = ⌈span ÷ post spacing⌉
- Posts = sections + 1 + gates (end/corner posts plus gate posts)
- Pickets = ⌈span × 12 ÷ (picket width + gap)⌉
Common questions
How many pickets do I need for 100 feet?
At the standard 5.5 in picket with no gap (privacy), 100 ft takes about 218 pickets. With a 4 ft gate (96 ft of fence), it is 210. The calculator rounds to whole pickets and accounts for the gate.
How far apart should fence posts be?
8 ft is the standard for wood fences — wide enough to be economical, narrow enough that rails do not sag. Use 6 ft spacing for 8 ft tall privacy fences or high-wind areas, and never exceed 10 ft between posts.
How many bags of concrete per fence post?
One 50 lb bag per post hole for a 4 ft fence in normal soil; two bags for 6 ft privacy fence posts or loose soil. Aim for a hole 1/3 of the post's above-ground height and about 3× the post width.
How deep do fence posts need to be?
Rule of thumb: bury 1/3 to 1/2 of the above-ground height. A 6 ft privacy fence wants 2-3 ft of post in the ground, with a gravel base for drainage so the post bottom does not sit in water. Check local frost depth — posts set above frost line heave.
Should I space pickets for wind load?
A full privacy fence catches wind like a sail; in exposed areas use 1-2 in gaps or a shadowbox (alternating faces) pattern, or step down to 5 ft height. The gap also slows warping by letting the boards breathe.