How to use the fence calculator
Enter the total length of the fence line in feet, including gate openings, and the fence height. Choose the post spacing: 8 ft on center is common for wood privacy fences built with 8 ft rails; 6 ft makes a stiffer fence in windy places and with heavier boards. Add your gates and their width.
For pickets, enter the actual width (a 1×6 is 5.5 in, a 1×4 is 3.5 in) and the gap between pickets: 0 for a privacy fence, a few inches for a picket fence. The hole size drives the concrete count.
How the materials are counted
- Fence line = total length − gate openings
- Sections = fence line ÷ post spacing, rounded up
- Posts = sections + 1 + one per gate (each gate needs a post on both sides)
- Rails = sections × 2 for fences up to 4 ft, × 3 for taller fences
- Pickets = fence line (in) ÷ (picket width + gap), plus 5% for splits and bad boards
- Concrete: each hole's volume minus the post and a 6 in gravel base, plus 10%, in 80 or 50 lb bags
The count is for one straight run. Each corner on a fence line is just another post, so if your run has corners that don't fall on a regular post position, add one post per corner.
Materials by fence length
6 ft privacy fence, 1×6 pickets with no gap, one 4 ft gate, 10 in holes 30 in deep:
| Length | Posts, 8 ft spacing | Rails | Pickets | 80 lb bags | Posts, 6 ft spacing |
|---|---|---|---|---|---|
| 50 ft | 8 | 18 | 106 | 14 | 10 |
| 75 ft | 11 | 27 | 163 | 19 | 14 |
| 100 ft | 14 | 36 | 220 | 24 | 18 |
| 150 ft | 21 | 57 | 335 | 36 | 27 |
| 200 ft | 27 | 75 | 450 | 46 | 35 |
Worked example: a picket fence
A 60 ft front-yard picket fence, 4 ft tall, with one 3 1/2 ft gate. 1×4 pickets (3.5 in) with 2 1/2 in gaps, posts 8 ft apart.
- Fence line: 60 − 3.5 = 56.5 ft.
- Sections: 56.5 ÷ 8 = 7.06, rounded up = 8. Posts: 8 + 1 + 1 = 10.
- Rails: a 4 ft fence takes 2 per section, so 16.
- Pickets: 678 in ÷ 6 in (3.5 + 2.5) = 113, plus 5% = 119.
- Concrete: 17 bags of 80 lb mix for 10 holes.
Post length and depth
A common rule is to bury about a third of the post's above-ground height, and always below your frost line. A 6 ft fence on 8 ft posts leaves 2 ft in the ground; set on a 6 in gravel base, that's a 30 in hole. In cold climates, the frost line can be deeper than that; your building department can tell you its depth. Gate posts carry the most load, so many builders use 6×6 posts or deeper holes there.
Call 811 before you dig: it's free and marks buried lines. Many cities and HOAs limit fence height (often 4 ft in front yards and 6 ft in back yards) and require a permit, and the fence must sit on your side of the property line.
Questions people ask
How many pickets for an 8 ft section?
With 1×6 pickets (5.5 in) and no gap, 96 ÷ 5.5 = 17.5, so 18 pickets. With 1×4 pickets and 2 1/2 in gaps, 96 ÷ 6 = 16.
Should fence posts be 6 or 8 ft apart?
8 ft is standard for wood fences because rails come in 8 ft lengths. Use 6 ft for heavy boards, tall fences, windy sites and vinyl panels sized for 6 ft.
How much concrete per fence post?
A 4×4 post in a 10 in hole, 30 in deep with 6 in of gravel, takes about 0.92 cu ft: 2 bags of 80 lb mix. Our fence post concrete guide has a chart by hole size.