Area unit converter

The calculator converts area between mm², cm², dm², m², ares, hectares and km². Choose the unit of the area you enter and the unit of the result next to the boxes. A field of 1 hectare is 10,000 m², roughly a square 100 metres on each side, somewhat more than a football pitch.

How it works

A square metre is the area of a square with sides of 1 metre. Measured in decimetres, the side is 10 dm, and the area of a square is 10 · 10 = 100 dm². That is why area is converted in hundreds, not tens.

A few typical conversions:

• 1 ha = 10,000 m²,
• 8 ares of garden = 800 m²,
• a 65 m² flat = 650,000 cm²,
• 2,500 cm² = 0.25 m² (for example, a 50 × 50 cm table top).

Things to watch out for

A classic mistake is converting area the same way as length: 1 m² = 100 dm², not 10 dm², and 1 m² = 10,000 cm², not 100 cm². If you are unsure, picture the area as a rectangle and convert each side separately. A rectangle 2 m × 3 m has 6 m²; in centimetres it is 200 cm × 300 cm = 60,000 cm².

When working out the area of a rectangle, it is simplest to convert the sides to the same unit first, multiply them, and only then convert the result here. You can find a summary of area formulas in the article on volumes and areas.