Fence Calculator — Posts & Sections
Enter the fence length and post spacing to get the number of posts and sections required.
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How it works
sections = ceil(length ÷ spacing); posts = sections + 1
Fence length to enclose a square lot
| Lot size | Side length | Fence perimeter |
|---|---|---|
| ¼ acre (10,890 sq ft) | 104 ft | 417 ft |
| ½ acre (21,780 sq ft) | 148 ft | 590 ft |
| 1 acre (43,560 sq ft) | 209 ft | 835 ft |
| 2 acres (87,120 sq ft) | 295 ft | 1,181 ft |
| 5 acres (217,800 sq ft) | 467 ft | 1,867 ft |
Assumes a square lot — the most fence-efficient shape. A long, narrow lot of the same acreage needs more fencing. Enter your measured perimeter above to get exact posts and sections.
Frequently asked questions
How many fence posts do I need for 100 feet?
At 8 ft post spacing, a straight 100 ft run needs 13 sections and 14 posts (one more post than sections). At tighter 6 ft spacing it is 17 sections and 18 posts. Add one extra post at every corner and on each side of a gate.
How many pickets do I need for a fence?
For a privacy fence with 5½-inch-wide pickets butted together, figure about 2.2 pickets per linear foot — roughly 220 pickets per 100 ft. With a small gap between boards it is closer to 2 per foot, about 200 per 100 ft. Add ~10% for waste.
How much fence do I need to enclose an acre?
A square 1-acre lot is about 209 ft on a side, so roughly 835 linear feet of fence. A quarter acre is about 417 ft and a half acre about 590 ft. Rectangular or irregular lots need more — measure your actual perimeter.