Wood Fence Calculator
This wood fence calculator returns posts, rails, and board counts for privacy, picket, shadowbox, and board-on-board styles. Enter your fence length, height, and style below to get a complete materials list for any wood fence.
Advanced: Picket Width & Gap
13 line + 2 gate, 4x4
With 5% waste: 38 rails, 215 pickets/boards.
Hole: 10 in diameter x 2 ft deep, 0.92 cu ft per post.
Total: 30 bags (80 lb) / 45 bags (60 lb) / 45 bags (50 lb) for 15 posts, 13.81 cu ft.
A wood fence calculator has to account for four different board layouts before it can answer how much lumber a job needs: privacy, picket, shadowbox, and board-on-board. Each style uses the same post and rail math but a different board width, gap, and board count per section, so the difference between styles can be 100 boards or more on the same 100-ft run. This tool applies the fence calculator formulas from the material calculators hub to whichever wood style you pick, and the fence post calculator breaks the post math out on its own if that's the only number you still need.
Wood Fence Calculator Formula
- Subtract gate width from total length, then divide by post spacing (8 feet is standard) and round up for sections.
- Posts = sections + 1, plus 2 per gate opening.
- Rails per section run 2 for a 4-ft fence, 3 for 5–6 ft, 4 above 6 ft; multiply by sections for total rails.
- Clear space per section = post spacing in inches minus the post's actual width (92.5 inches for an 8-ft section with a 4×4 post).
- Boards per section = clear space ÷ (board width + gap), style-dependent as shown below, then multiply by sections and add 5% waste.
Worked example — 100 feet, 6-ft privacy fence, one 4-ft gate: 96 feet of fence line over 12 sections needs 13 line posts + 2 gate posts = 15 posts, and 12 × 3 = 36 rails at a 6-ft height. Each section fits 92.5 ÷ 5.5 = 16.8, rounded up to 17 pickets, so 12 × 17 = 204, or 215 pickets with 5% waste.
Wood Fence Style Comparison at 100 Feet
Posts (14) and rails (39) stay the same across styles at 6 feet tall, 8-ft spacing, no gate — only the board count changes by style.
| Style | Board width + gap | Boards per section | Boards (raw) | Boards (+5% waste) |
|---|---|---|---|---|
| Privacy (1×6 dog-ear) | 5.5 in, no gap | 17 | 221 | 233 |
| Picket (1×4 spaced) | 3.5 in + 2.5 in gap | 16 | 208 | 219 |
| Shadowbox (boards both sides) | 5.5 in + 2.5 in gap, ×2 | 24 | 312 | 328 |
| Board-on-board (1-in overlap) | 4.5 in effective | 21 | 273 | 287 |
Shadowbox alternates boards on the front and back of the rails with a gap between them on each side, so the total board count doubles the per-side figure — 12 boards per side becomes 24 per section. Board-on-board overlaps each 5.5-inch board by 1 inch, giving an effective coverage width of 4.5 inches per board with zero gap and no sightline through the fence.
Horizontal Wood Fence Boards by Height
A horizontal fence stacks 1×6 boards up the height of each section instead of running them vertically, so board count depends on fence height, not post spacing.
| Fence height | Boards per section (1×6, 0.5-in gap) |
|---|---|
| 4 ft | 8 |
| 6 ft | 12 |
| 8 ft | 16 |
A 100-ft horizontal fence at 6 feet tall and 13 sections needs 156 boards, or 164 with 5% waste.
Materials List for a Wood Fence
- Pickets/boards: 1×6 for privacy, shadowbox, and board-on-board; 1×4 for picket style, cut to your fence height plus ground clearance.
- Posts: 4×4 for line posts up to 6 feet, 6×6 for gate posts and any fence over 6 feet, in 8- to 16-ft stock lengths.
- Rails: 2×4 rails matching your post spacing, 2 to 4 per section depending on height.
- Fasteners: roughly 2 screws or nails per board per rail crossing.
See the picket fence calculator and fence board calculator for style-specific charts at more lengths, and the fence materials compared guide if you're still deciding between wood and another material.
Cedar, pressure-treated pine, and redwood are the three most common wood species for a fence build, each trading upkeep for appearance and lifespan. Pressure-treated pine resists rot without a stain or seal, cedar naturally resists insects and holds up well untreated, and redwood offers the richest natural color of the three. Species choice does not change the board count above — it only changes how often the fence needs refinishing and how long it lasts before boards need replacing.
Nominal lumber dimensions run smaller than their name suggests across every board and post in this calculator: a "1×6" board actually measures about 0.75 by 5.5 inches, and a "4×4" post actually measures about 3.5 by 3.5 inches. This calculator uses those actual dimensions throughout, not the nominal names printed on the lumber tag, which is why the numbers above may look slightly different from a rough mental estimate.
Post Depth and Concrete
Every wood fence style uses the same footing rule: bury posts at least a third of total height, 2 feet minimum, in a hole roughly three times the post's actual width — 10 inches for a 4×4, 12 inches for a 6×6. The concrete per fence post calculator converts that hole size into a bag count. Call 811 before digging to get utility lines marked.
Waste and Ordering
Add 5% to boards and rails for cutting errors and warped lumber — the gap between 204 raw pickets and 215 ordered in the worked example above. Posts and concrete don't need a waste allowance since they aren't cut to non-standard lengths on site.
Next Steps
Once your board, rail, and post counts are set, the wood fence cost calculator turns those quantities into an installed cost range by material and labor.