Calculate pickets, posts, and rails for a board fence.
Shopping list
Estimated cost
Usage Tip
Set corner and gate posts first, then space the line posts evenly between them; leave a small gap between pickets for wood movement.
posts = round up( length ÷ post spacing ) + 1
rails = posts × 2
Counts round up to whole pieces.
How many fence boards do I need?
Start with the run length and the style. Divide the fence length by the coverage of one board — its width plus the gap — and you have the board count. Privacy fences butt the boards tight; picket fences leave a gap; board-on-board and shadowbox overlap, so they use noticeably more material. This calculator does the count for every style and then adds the posts, rails, concrete, fasteners and cost so you leave for the yard with a real list.
Fence board spacing guide
The gap between boards is what defines the look and the board count.
| Style | Typical gap | Coverage per board |
|---|---|---|
| Privacy (butted) | 0 in | board width |
| Picket | 1-1/2 to 3 in | width + gap |
| Board-on-board | overlap 1 in | width minus overlap |
| Shadowbox | boards both sides | about 1.5x a gapped fence |
Fence styles
Picket
Evenly spaced vertical boards with a visible gap. Classic front-yard look, least material.
Privacy
Vertical boards butted edge to edge for a solid screen. No gap, maximum boards for a single-sided fence.
Board-on-board
Vertical boards overlapped so there is no see-through gap even as the wood shrinks. Uses more boards than privacy.
Shadowbox
Boards alternate front and back, each covering the gap on the opposite side. Looks finished from both sides and is wind-friendly, but roughly doubles the boards.
Horizontal slat
Boards run horizontally between posts in rows up the height. Modern look; board length is set by the post spacing.
Posts and rails
Posts are spaced 6 or 8 ft on center; a run needs one more post than sections, plus an extra at each corner and gate. Rails run between posts: two rails for fences up to about 5 ft, three rails for 6 ft and taller. Set posts about one-third of their length in the ground.
Privacy fence material chart
Boards for 100 ft of solid privacy fence using common board widths, butted with no gap.
| Board | Actual width | Boards per 100 ft |
|---|---|---|
| 1x4 | 3-1/2 in | about 343 |
| 1x6 | 5-1/2 in | about 219 |
| 5/4x6 | 5-1/2 in | about 219 |
Picket spacing chart
Pickets for 100 ft using a 5-1/2 in board at common gaps.
| Gap | Coverage | Pickets per 100 ft |
|---|---|---|
| 1-1/2 in | 7 in | about 172 |
| 2 in | 7-1/2 in | about 160 |
| 3 in | 8-1/2 in | about 142 |
Posts and concrete
Each post is usually set in concrete. A typical 10 in diameter hole 24 in deep takes about two 60 lb bags of concrete mix per post once the post is allowed for. Taller or windy-site fences use deeper holes and more concrete.
Estimating cost
Total material cost is the sum of boards, posts and rails, plus concrete and fasteners. Dividing by the run gives a cost per linear foot, which is the easiest way to compare quotes or styles. Add 10 percent waste for cuts and the occasional bad board.
Frequently asked questions
How many fence boards per foot?
Divide 12 by the board coverage in inches. A 5-1/2 in board butted tight is about 2.2 boards per foot; with a 2 in gap it drops to about 1.6 per foot.
How far apart should fence posts be?
6 to 8 ft on center. 8 ft uses fewer posts; 6 ft is sturdier and standard for tall privacy fences.
How many rails do I need?
Two for fences up to about 5 ft, three for 6 ft and taller. Multiply by the number of sections.
Why does shadowbox use so many more boards?
It places boards on both faces of the fence, offset to cover the gaps, so you roughly double the board count of a single-sided fence.
How much concrete per fence post?
About two 60 lb bags for a standard 10 in by 24 in hole. Confirm with your post size and local frost depth.
How much waste should I add?
About 10 percent for straight runs, more for angled or stepped fences and for picket tops that are cut on site.
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Estimates are for planning. Board coverage, post depth, concrete needs and local code vary; confirm hole depth against your frost line and verify quantities with a final site measurement before buying.