Area Unit Converter
Square metres, hectares, mu and square feet — all units at once.
Inputs
Result
Formula
| Metric | 1 m² = 10 000 cm² = 1 000 000 mm² |
| Land | 1 ha = 10 000 m² = 15 mu, 1 mu = 666.67 m² |
| Imperial | 1 ft² = 144 in² = 0.092903 m², 1 yd² = 9 ft² |
| Acre | 1 acre = 4 840 yd² = 4 046.86 m² ≈ 6.07 mu |
| General rule | target = source value × source factor ÷ target factor |
One mu is 666.6667 m², roughly one and a half basketball courts; one hectare is 15 mu. A 100 m² apartment floor area is about 0.15 mu.
Area and land unit reference
| Unit | Symbol | In m² | In mu | Typical use |
|---|---|---|---|---|
| Square metre | m² | 1 | 0.0015 | Floor area |
| Hectare | ha | 10000 | 15 | Site area |
| Mu | mu | 666.67 | 1 | Farmland, land transfer |
| Square kilometre | km² | 1000000 | 1500 | Regional area |
| Square foot | ft² | 0.0929 | 0.000139 | Imported plant footprint |
| Square yard | yd² | 0.8361 | 0.00125 | Carpet, fabric |
| Acre | acre | 4046.86 | 6.07 | Overseas farms |
FAQ
Why is one mu such an odd 666.67 square metres?
Because mu comes from the Chinese system where the chi is 1/3 m. One mu is 60 square zhang = 6000 square chi, and one square chi is 1/9 m², so 1 mu = 6000 ÷ 9 = 666.67 m². Remember just two numbers on site: 1 mu ≈ 667 m², 1 hectare = 15 mu.
How do gross, internal and usable floor area differ?
Gross floor area is measured to the outside face of the external walls and includes walls and shared circulation; internal area is what the party walls enclose within your door; usable area subtracts the walls themselves. There is no fixed ratio — the gap between them runs 15-25% between units in the same building, so multiplying by 0.8 is not valid.
Can roof area be taken from floor area?
No. Flat roofs still add eaves, parapet inner faces and falls; pitched roofs must be increased by the slope factor — 1/cos30° = 1.155 at 30°, so projected area times 1.155. With dormers and rooflights the true developed area often exceeds the projection by over 20%.
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Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.