Resource
Fencing Guide
Estimate fence length, posts, and rolls for rectangular and square fields — with tables for common acreages from 1 to 640 acres.
Fence estimator
Enter your field and we'll estimate perimeter, fence length, posts, and rolls to buy. Toggle between feet and rods.
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Fence details
Perimeter
1,980 ft
120 rods
Area
5 ac
217,800 sq. ft.
Fence needed
2,004 ft
incl. 24 ft for wraps
Rolls to buy
7
@ 330 ft each
Total posts
198
4 corner + 194 line
Estimates only. Add extra for splices, terrain, and stretch. One rod = 16½ ft.
Rectangular fields — reference table
For rectangular or oblong fields with square corners, twice the length plus twice the width gives the total fence length. Add extra to wrap around end and corner posts.
| Acres | Length (ft) | Length (rods) | Width (ft) | Width (rods) | Fence (ft) | Fence (rods) |
|---|---|---|---|---|---|---|
| 1 | 264 | 16 | 165 | 10 | 858 | 52 |
| 1 | 330 | 20 | 132 | 8 | 924 | 56 |
| 1¼ | 330 | 20 | 165 | 10 | 990 | 60 |
| 2½ | 660 | 40 | 165 | 10 | 1,650 | 100 |
| 4 | 528 | 32 | 330 | 20 | 1,716 | 104 |
| 5 | 660 | 40 | 330 | 20 | 1,980 | 120 |
| 6 | 990 | 60 | 264 | 16 | 2,508 | 152 |
| 7 | 1,320 | 80 | 264 | 16 | 3,168 | 192 |
| 8 | 1,320 | 80 | 297 | 18 | 3,234 | 196 |
| 10 | 825 | 50 | 528 | 32 | 2,706 | 164 |
| 15 | 1,320 | 80 | 495 | 30 | 3,630 | 220 |
| 20 | 1,650 | 100 | 528 | 32 | 4,356 | 264 |
| 25 | 1,320 | 80 | 825 | 50 | 4,290 | 260 |
| 30 | 1,320 | 80 | 990 | 60 | 4,620 | 280 |
| 40 | 1,650 | 100 | 1,056 | 64 | 5,412 | 328 |
| 50 | 1,650 | 100 | 1,320 | 80 | 5,940 | 360 |
| 60 | 1,980 | 120 | 1,320 | 80 | 6,600 | 400 |
| 70 | 2,640 | 160 | 1,155 | 70 | 7,590 | 460 |
| 80 | 2,112 | 128 | 1,650 | 100 | 7,524 | 456 |
| 100 | 2,640 | 160 | 1,650 | 100 | 8,580 | 520 |
| 120 | 3,168 | 192 | 1,650 | 100 | 9,636 | 584 |
| 140 | 4,620 | 280 | 1,320 | 80 | 11,880 | 720 |
| 160 | 5,280 | 320 | 1,320 | 80 | 13,200 | 800 |
| 320 | 6,600 | 400 | 2,112 | 128 | 17,424 | 1,056 |
| 640 | 6,600 | 400 | 4,224 | 256 | 21,648 | 1,312 |
Square fields — reference table
For square fields, four times the length of one side gives the fence required. Add at least 3 ft per corner, end, or gate post for wrapping.
| Acres | Side (ft) | Side (rods) | Fence (ft) | Fence (rods) |
|---|---|---|---|---|
| 1 | 208.75 | 12.65 | 835 | 50.61 |
| 2 | 295.17 | 17.89 | 1,180.67 | 71.56 |
| 2½ | 330 | 20 | 1,320 | 80 |
| 3 | 361.5 | 21.91 | 1,446 | 87.64 |
| 4 | 417.42 | 25.3 | 1,669.67 | 101.19 |
| 5 | 466.25 | 28.26 | 1,866.67 | 113.13 |
| 6 | 511.17 | 30.98 | 2,045 | 123.94 |
| 7 | 552.17 | 33.46 | 2,208.67 | 133.86 |
| 8 | 590.33 | 35.78 | 2,361.33 | 143.11 |
| 9 | 626.17 | 37.95 | 2,504.67 | 151.8 |
| 10 | 660 | 40 | 2,640 | 160 |
| 15 | 933.42 | 56.57 | 3,733.67 | 226.28 |
| 20 | 1,043.58 | 63.25 | 4,174.33 | 252.99 |
| 25 | 1,143.17 | 69.28 | 4,572.67 | 277.13 |
| 40 | 1,320 | 80 | 5,280 | 320 |
| 50 | 1,475.83 | 89.44 | 5,903.33 | 357.78 |
| 60 | 1,616.67 | 97.98 | 6,466.67 | 391.92 |
| 70 | 1,746.17 | 105.83 | 6,984.67 | 423.31 |
| 80 | 1,807.5 | 109.55 | 7,230 | 438.18 |
| 90 | 1,866.75 | 113.14 | 7,467 | 452.55 |
| 100 | 2,087.08 | 126.49 | 8,348.33 | 505.96 |
| 120 | 2,286 | 138.55 | 9,145.33 | 554.26 |
| 140 | 2,469.5 | 149.67 | 9,878 | 598.67 |
| 160 | 2,640 | 160 | 10,560 | 640 |
| 320 | 3,733.58 | 226.28 | 14,934.33 | 905.11 |
| 640 | 5,280 | 320 | 21,120 | 1,280 |
Post spacing, depth & materials
| Line-post spacing (woven wire) | 10–14 ft (~0.6–0.85 rod) on level ground; tighter on uneven terrain |
| Line-post spacing (barbed wire) | 12–20 ft (~0.73–1.21 rod) depending on wire tension |
| Corner / end / gate posts | Set at least 3½ ft deep and braced (H-brace assembly) |
| Line-post depth | Roughly ⅓ of post length below grade (~2½–3 ft typical) |
| Concrete for corner posts | About ½ – 1 bag (60 lb) per hole |
| Standard woven wire roll | 330 ft (20 rods) |
| Standard barbed wire spool | 1,320 ft (80 rods · ¼ mile) |
| Typical walk-gate width | 4 ft |
| Typical equipment gate width | 10 – 16 ft |
| Livestock crowd gate width | 16 – 20 ft |
Handy fencing formulas
- Rectangular perimeter: P = 2 × (L + W)
- Square side from acres: side = √(acres × 43,560)
- Acres from feet: acres = (L × W) ÷ 43,560
- Rod conversion: 1 rod = 16½ ft · 1 mile = 320 rods = 5,280 ft
- Feet ↔ rods: rods = ft ÷ 16.5 · ft = rods × 16.5
- Line posts along a run: posts = ceil(length ÷ spacing) + 1
- Rolls to buy: rolls = ceil(total fence ÷ roll length)
Linear measure (U.S.)
| Inches | Feet | Yards | Rods | Furlongs | Miles |
|---|---|---|---|---|---|
| 1 | .08333 | .02778 | .00505 | .000126 | .0000158 |
| 12 | 1 | .33333 | .06061 | .00152 | .000189 |
| 36 | 3 | 1 | .18182 | .00455 | .000568 |
| 198 | 16.5 | 5.5 | 1 | .025 | .003125 |
| 7,920 | 660 | 220 | 40 | 1 | .125 |
| 63,360 | 5,280 | 1,760 | 320 | 8 | 1 |
Read across: each row is the same distance expressed in every column.
Square & land measure (U.S.)
| Sq. In. | Sq. Ft. | Sq. Yd. | Sq. Rods | Acres | Sq. Miles |
|---|---|---|---|---|---|
| 1 | .00694 | .000772 | — | — | — |
| 144 | 1 | .11111 | — | — | — |
| 1,296 | 9 | 1 | .03306 | .000207 | — |
| 39,204 | 272.25 | 30.25 | 1 | .00625 | .0000098 |
| — | 43,560 | 4,840 | 160 | 1 | .0015625 |
| — | — | 3,097,600 | 102,400 | 640 | 1 |
Dimensions given are exact. When buying fence, add extra to cover wire taken up in wrapping corner and end posts and in splices.