Acreage calculator
Land area in acres, hectares, square feet and square metres
Pick the plot's shape and type its sides. The example is a plot 330 ft by 132 ft, exactly one acre.
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- Hectares
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- Square feet
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- Square metres
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- Square yards
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- Guntha (used in India)
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- Cents (used in India)
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A measurement from the sizes you typed. No waste allowance applies here. Check anything covered by a building code, or that you will pay for, against your own measurements.
How the acreage is worked out
An acre is 43,560 square feet, which is 4,046.86 square metres. The calculator finds the plot's area in square feet or metres, then divides. A hectare is 10,000 m², about 2.47 acres.
- Rectangle: length x width.
- Triangle: from its three sides by Heron's formula, so no angle or height is needed.
- Four sides and a diagonal: the diagonal splits the plot into two triangles: sides 1 and 2 with the diagonal, and sides 3 and 4 with the diagonal. Each is worked out by Heron's formula and the two are added. Four sides alone are not enough, because the same four sides can enclose different areas.
Worked example
330 ft x 132 ft = 43,560 sq ft, exactly 1 acre, or 0.4047 hectares. A plot of 100 m x 100 m is 1 hectare, or 2.471 acres.
Guntha and cents
In parts of India land is measured in guntha (33 ft x 33 ft = 1,089 sq ft; 40 guntha make an acre) and cents (one hundredth of an acre, 435.6 sq ft). Bigha, kanal and other local units differ from state to state, so they are not shown.
Limits
This treats the plot as flat with straight sides. Sloping or curved boundaries need a survey. Only a licensed surveyor's figure, or the official land record, settles a legal boundary or a sale area.
Defaults and where they come from
Every default is only a starting point. Change any box to match what you are buying or building.
| Default | Value | Source |
|---|---|---|
| Acre | 43,560 sq ft = 4,046.8564224 m² | Exact: US survey and international acre are defined from the foot (NIST SP 811). |
| Guntha and cent | 1 guntha = 1,089 sq ft (33 ft x 33 ft); 1 cent = 435.6 sq ft | Fixed units used in Indian land records (40 guntha or 100 cents to the acre). |
| Waste allowance | None | This page measures area only. |