Plot Size Calculator
Work out the area of a plot from its length and width in feet, metres, pieds or toises, and get the result in perches, toises and m².
Multiply the length by the width to get the area, then divide square metres by 42.21 for perches or by 3.799 for toises. Enter the sides in feet, metres, pieds or toises and the calculator does the conversion.
Plot area
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How it works
Area = length × width. For an irregular four-sided plot, the calculator averages the two lengths and the two widths, which is the usual quick estimate. Your surveyor's plan (with the exact area in m²) always wins over this estimate.
1 perche = 42.21 m², 1 toise = 3.799 m², 1 arpent = 100 perches. A "pied" is the old French foot (0.3248 m), slightly longer than the English foot (0.3048 m).
Frequently asked questions
How do I calculate the size of a plot in perches?
Multiply length by width in metres to get m², then divide by 42.21. For example a plot of 20 m by 25 m is 500 m², or about 11.85 perches.
What if my plot is not a perfect rectangle?
Tick "Irregular plot" and enter all four sides. The calculator averages the two lengths and the two widths, which is a quick estimate. Your surveyor's plan gives the exact area.
Is a pied the same as a foot?
No. A pied is the old French foot of 0.3248 m, slightly longer than the English foot of 0.3048 m.