Area Converter (m², ft², acres, hectares)

Convert area between square millimetres, centimetres, metres and kilometres, square inches, feet and yards, acres, hectares, and square miles.

Square millimetre (mm²)
Square centimetre (cm²)
Square metre (m²)
Hectare (ha)
Square kilometre (km²)
Square inch (in²)
Square foot (ft²)
Square yard (yd²)
Acre (acre)
Square mile (mi²)

Area conversion reference

1 unitft²acreha
1 mm²0.0000010.00001076390.0000000002471050.0000000001
1 cm²0.00010.001076390.00000002471050.00000001
1 m²110.76390.0002471050.0001
1 ha10 000107 6392.471051
1 km²1 000 00010 763 900247.105100
1 in²0.000645160.006944440.0000001594230.000000064516
1 ft²0.09290310.00002295680.0000092903
1 yd²0.83612790.0002066120.0000836127
1 acre4 046.8643 56010.404686
1 mi²2 589 99027 878 400640258.999

Converting area units

Area is length squared, which is why area units behave differently from the length units they're built on — and why converting them trips people up. This tool converts between metric and imperial area units, plus the land-measure units acre and hectare, working through the square metre.

Why squaring changes the factors

If a metre is 100 centimetres, a square metre is 100² = 10 000square centimetres, not 100. The same applies across the board: 1 m² is about 10.76 ft² because a metre is 3.281 feet and 3.281² ≈ 10.76. Whenever you convert an area, the length factor gets squared — forgetting that is the single most common error.

Land measures

A hectare is a metric square 100 m on a side, so exactly 10 000 m². An acre is 4046.86 m², so roughly 0.4 hectares — or put the other way, a hectare is about 2.47 acres. There are exactly 640 acres in a square mile.

Worked example

A room 4 m × 5 m is 20 m², which is 20 × 10.764 ≈ 215.3 ft². A 2-hectare field is 20 000 m², or about 4.94 acres. To find an area from its dimensions first, the area of shapes calculator handles rectangles, circles, and triangles.

Exact, except where the unit is not

Conversions between metric and imperial areas follow exactly from the definition of the inch, so they carry no uncertainty. Two units need care for a different reason: the acre and thehectare are precise, but land is rarely a neat rectangle, so a stated area usually comes from a survey rather than a multiplication. And as always, the precision of the answer is set by the measurements rather than the conversion.