Fence Perimeter Calculator — How Much Fencing Do I Need?
Enter your plot length and width, choose whether you need fencing on all four sides or fewer, and subtract your gate openings to get the exact linear meters of fence material to order.
m
m
Sides to fence
m
m
Perimeter of selected sides minus gate openings — the linear meters of fencing to order
- 1
Full perimeter (4 sides)
2 × (20 + 15) = 70 - 2
Gate deduction
1 × 1.2 = 1.2 - 3
Net fence run
70 − 1.2 = 68.8
How does this calculator work?
Fence run = 2 × (length + width) for full rectangle, minus gate widths. For partial enclosures, use the selected sides only. Divide the net run by post spacing and add one corner post per fenced side. The net run in linear meters is the quantity to quote to your supplier.
Formula
How this is calculated
For a rectangular plot, the full perimeter is 2 × (length + width). If you only need three sides (for example an open driveway at the front), the run is length + 2 × width. Two short sides gives 2 × width, and one side (a rear boundary) equals the plot length. Gate openings are subtracted from the perimeter because those sections carry a gate rather than a fixed fence panel.
The post estimate divides the net fence run by the post spacing, rounds up, then adds corner posts equal to the number of fenced sides (a post is needed at every corner). For a full four-sided enclosure, four corner posts are added; for three sides, three; and so on. This is a planning-level estimate — gates, tight corners, and changes in grade will increase the actual post count, so add a few extra as a buffer.
The model assumes a simple rectangle. For irregular plots — L-shapes, curves, sloped boundaries — measure each straight segment separately, add them up, and enter the total as the fence length in a fence-material or fence-estimate calculator.
Frequently asked questions
No. Gate openings are deducted from the perimeter because you install a gate there, not a fence panel. Gate posts are included in the post estimate because posts are still needed on each side of the opening.
Measure each straight boundary separately and add them up. Enter that total directly into a fence-material or fence-estimate calculator rather than using this perimeter calculator.
The estimate assumes straight runs with evenly spaced posts. Gates require extra posts on each side, L-shaped runs add posts at internal corners, and terrain can force closer spacing. Always add a few extra posts as a buffer when ordering.
Also known as
TG we-Calculate Editorial Team. (2026). Fence Perimeter Calculator — How Much Fencing Do I Need? [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/fence-perimeter-calculator
TG we-Calculate Editorial Team. "Fence Perimeter Calculator — How Much Fencing Do I Need?." TG we-Calculate. 2026. https://we-calculate.com/calculator/fence-perimeter-calculator.
TG we-Calculate Editorial Team, "Fence Perimeter Calculator — How Much Fencing Do I Need?," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/fence-perimeter-calculator
@misc{wecalculate_fence_perimeter_calculator, title = {Fence Perimeter Calculator — How Much Fencing Do I Need?}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/fence-perimeter-calculator}}, year = {2026}, note = {TG we-Calculate} }
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