Fence Length Calculator
Measure a property boundary, deduct gates and estimate how many fence sections and posts you may need. Enter your boundary dimensions and preferred spacing to get a practical planning estimate.
Enter fence measurements
Select a boundary type and unit. Use the same unit for every measurement.
How fence length is calculated
The boundary perimeter is calculated first. Gate openings are then subtracted to estimate the length that needs fencing.
Rectangle perimeter = 2 × (length + width) Four-sided perimeter = side 1 + side 2 + side 3 + side 4 Net fence length = perimeter − total gate opening width Length with allowance = net fence length × (1 + allowance percentage ÷ 100) Estimated sections = round up (length with allowance ÷ section spacing)Example calculation
Suppose a rectangular property is 20 m long and 10 m wide. Its perimeter is 2 × (20 + 10) = 60 m. One 3 m gate leaves 57 m of fence. With a 5% allowance, the estimated material length is 59.85 m. At a maximum section spacing of 2.4 m, the calculator estimates 25 sections.
Understanding the post estimate
The post estimate is a simple planning figure based on the estimated section count, an endpoint allowance and two additional posts per gate. Actual layouts can require a different number because corner posts may be shared between fence runs, gates may need reinforced posts, and some fence systems use different post arrangements. Confirm the final layout against the manufacturer's instructions before ordering.
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