Field Boundary Fencing Length Calculator
Subtract gate openings from a rectangular field perimeter.
A QUICK WALKTHROUGH
How to use this tool
- Enter values in the labelled units.
- Calculate and review the result and limitations.
Formula and units
P = 2 × (L + W); G = n × g; F = P − G; m
Scope and limitations
For one rectangular boundary only. Gate width is the opening per gate, not the combined width. Excludes terrain, slopes, wastage, material allowance, posts and labour; it does not design a fence or establish a legal boundary.
Input and precision
Length and width must be positive; gate count must be a nonnegative integer and gate width nonnegative. Every value must be finite and no greater than 1,000,000,000; total gate width must not exceed perimeter. Results use floating-point arithmetic and display up to four decimal places; rounding does not improve accuracy.
Source
Independent arithmetic implementation. ToolFoundry source interface reviewed on 6 October 2026.
GOOD TO KNOW
Common questions
Are my values uploaded?
Values stay in this browser; they are not uploaded or stored.