Published August 13, 2026 · Updated August 23, 2026 · By Tupep
A yard is not a straight line
A quarter acre is 10,890 sq ft, which on a typical suburban lot is something like 75 ft of frontage by 145 ft deep. Nobody fences all of that. The house, driveway and front setback eat the front half, and what gets fenced is a backyard bounded on three sides with two short returns to the house wall. That is why a linear-foot calculator is not enough. You are doing a run-by-run takeoff where corners, terminal posts, gate openings and grade change the count.
The layout formula
Work run by run:
- Spaces = fence sections needed plus any gate openings in that run
- Post positions = spaces + 1
- Sections = run length minus gate openings, divided by max spacing, rounded up
Then add every run’s post positions and subtract one post for each shared corner, because a corner post belongs to two runs and you buy it once. That subtraction is the most common error in a whole-property takeoff.
Worked example
Backyard is 75 ft wide across the back and 70 ft deep on each side, fenced on three sides and tied into the house at both ends. Total fence line is 70 + 75 + 70 = 215 ft. There is a 10 ft double drive gate near the house on the west run and a 4 ft walk gate in the back run. Maximum spacing is 8 ft.
- Run A, west side, 70 ft. Minus the 10 ft gate leaves 60 ft of fence. 60 / 8 = 7.5, round up to 8 sections at 7.5 ft. Spaces = 8 + 1 gate = 9. Post positions = 10.
- Run B, back, 75 ft. Minus the 4 ft gate leaves 71 ft. 71 / 8 = 8.875, round up to 9 sections at 7.89 ft. Spaces = 9 + 1 = 10. Post positions = 11.
- Run C, east side, 70 ft. No gate. 70 / 8 = 8.75, round up to 9 sections at 7.78 ft. Spaces = 9. Post positions = 10.
Add them: 10 + 11 + 10 = 31. Subtract the two shared corners and you buy 29 posts. Sections total 8 + 9 + 9 = 26, and fabric length is 215 minus 14 ft of gate openings, or 201 ft.
| Post role | Count | Size | Why |
|---|---|---|---|
| Line posts | 22 | 4×4 x 8 ft | Carry rails from both sides, loads cancel |
| Corner posts | 2 | 4×4 or 6×6 x 8 ft | Rails pull in two directions at 90 degrees |
| Terminal post at house | 1 | 4×4 x 8 ft | Rails pull one way only |
| Gate posts | 4 | 6×6 x 10 ft | Carry hinge and latch loads, set deepest |
| Total | 29 |
Corner and terminal posts are not the same animal as line posts. On a line post the rail tension from the left cancels the tension from the right. On a corner or terminal the pull is one sided, which is why those get set deeper, get a bigger hole, or get braced back into the line. Gate posts are worse again, because a gate is a lever that spends its life trying to rotate the hinge post out of the ground.
Material takeoff from the run data
Pickets follow the fabric length, not the fence line. 201 ft is 2412 in. At a 5.75 in module, a 5.5 in picket face plus a 1/4 in gap, that is 2412 / 5.75 = 419.5, so 420 pickets. Add 5 percent and order 440.
Rails are three per section: 26 times 3 is 78 rails. Your longest bay is 7.89 ft, so 8 ft rail stock covers every bay with nothing left over. That is tight, and if a bay creeps a quarter inch you have no rail to trim, so we buy a few 10 ft rails for the long bays.
| Item | Quantity | How it was derived |
|---|---|---|
| Posts | 29 | 31 positions minus 2 shared corners |
| Rails, 2×4 | 78 plus spares | 26 sections x 3 |
| Pickets, 1×6 | 440 | 420 net plus 5 percent |
| Concrete, 80 lb bags | about 105 | 3 per line post hole, 7 per gate post hole |
| Gate hardware sets | 2 | Walk gate and double drive gate |
The concrete comes from two hole sizes. A 12 in hole 30 in deep for a 4×4 needs about 1.75 cu ft net, or three 80 lb bags at 0.6 cu ft each. A 16 in hole 42 in deep for a 6×6 gate post needs about 4.15 cu ft, or seven bags. Twenty five posts at three bags is 75, plus four gate posts at seven is 28, for 103.
Grade is the part people forget
Property lines are flat on paper and never flat in dirt. If the back run drops 30 in across its 75 ft, you choose between stepping and racking. A stepped fence keeps every panel level and drops it at each post, so the 9 sections in that run step down about 3-1/3 in each. A racked fence follows the grade with parallelogram panels and needs no steps, but pickets get cut on an angle top and bottom.
Either way, the low end needs longer posts, because the downhill post has to catch the top rail of the uphill panel and reach the ground on the downhill side. Budget 10 ft posts for the bottom third of any sloped run.
Before you dig
Post depth, frost depth, fence height limits and property line setbacks are all jurisdiction dependent. Confirm every one of them with your local building department, and have your utilities located before the auger touches the ground. Many places also require the finished face to point toward the neighbor, which changes nothing in your quantities but changes which side the rails land on.
Measure to the survey pins, not the lawn edge or the neighbor’s old fence. We have seen more than one fence rebuilt because the takeoff was accurate and the line was not.
Related guides
- Post Spacing: 6 ft vs 8 ft
- Gate Framing: What the Calculator Does Not Count
- How Many Posts and Pickets for a 100 ft Privacy Fence
- Picture Frame Border: Extra Boards and Blocking
Sources and Further Reading
Run your own numbers with the Fence Calculator, or browse every tool on the calculators index. Coverage figures and material constants are cross-checked against manufacturer technical data sheets before publication. See our Methodology page for how figures are selected and verified.
Planning estimate only. Results assume standard conditions and are intended for material planning. Verify against your product’s technical data sheet and your local building code before purchasing. Structural, electrical, and gas work should be specified by a licensed professional.
Last updated: August 23, 2026
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