Free fence calculator
Find the exact number of posts, rails, and pickets for your wood fence — just enter your perimeter, post spacing, and picket size.
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Estimates only. Quantities are minimums — add 5–10% for waste and cuts. Verify post spacing with local building codes before purchasing materials.
Results are estimates. Consult a professional.
How the fence materials calculator works
The calculator starts with your fence perimeter and post spacing, then works outward to count every structural piece you need: posts, rails, and pickets. Each number follows from the one before it, so the only inputs that matter are the perimeter, your chosen spacing, the number of rails per section, and the picket width and gap you want.
Worked example: 100 ft backyard fence
Sarah is enclosing a 100 ft backyard run with standard dog-ear pickets. She is using 8 ft post spacing, 3 rails per section, 3½-inch wide pickets and a ¼-inch gap between pickets.
Fence materials for common backyard runs
These figures assume 8 ft post spacing, 3 rails per section, 3½-inch pickets with a ¼-inch gap, and no gate openings. Add 5–10% to every count for waste and cuts before you order.
| Perimeter | Sections | Posts | Rails | Pickets |
|---|---|---|---|---|
| 50 ft | 7 | 8 | 21 | 160 |
| 100 ft | 13 | 14 | 39 | 320 |
| 150 ft | 19 | 20 | 57 | 480 |
| 200 ft | 25 | 26 | 75 | 640 |
| 300 ft | 38 | 39 | 114 | 960 |
Based on 8 ft post spacing, 3 rails/section, 3½ in pickets + ¼ in gap. Gate openings reduce picket count and section count proportionally.
Practical tips before you order
A materials list is only as good as the perimeter measurement behind it. Walk the property line with a 100-ft tape rather than estimating from a plot plan — surveyed lot dimensions are to the property line, not to where you can actually dig posts. Utility lines, easements, and setback requirements can all shift your true fence line inward.
- Order 5–10% extra pickets. End cuts, splitting, and boards with knots in the wrong place eat into your count more than most people expect.
- Post spacing drives everything. Standard 8 ft spacing works for most 6-ft privacy fences; windy or hilly sites benefit from 6 ft spacing to keep rails from sagging.
- Gate posts need to be set deeper. A 6-ft fence gate post should go at least 3 ft in the ground (half the above-grade height plus 6 in). Factoring those holes into your concrete order is where the concrete calculator comes in handy.
- Rails and pickets are sold in fixed lengths. Common rail lengths are 8 ft and 16 ft; pickets are 6 ft or 8 ft. Round up to the next full board when converting your counts to purchase quantities.
Accuracy and limitations
The post, rail, and picket formulas are exact given the inputs you enter. Real-world totals diverge from the calculator's output in a few predictable ways: corners always consume an extra post, a curved fence line is longer than a straight-line perimeter estimate, and sloped terrain means posts come in different heights rather than uniform 8-ft lengths.
The calculator assumes a straight, flat run with no gates or corners beyond what's already in the perimeter. It does not account for post-cap boards, kickboards, concrete for post holes, or hardware (screws, brackets, hinges). Use those figures as a starting point and adjust for your site conditions before you load up the truck.
Fence materials definitions
About this fence materials calculator
This calculator runs entirely in your browser. No measurements are sent to any server, and no account is needed. Enter your perimeter, spacing, and picket dimensions and the counts update instantly.
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