Convert an area measurement
- Choose area entry and its unit, or enter the length and width of a rectangle in a common unit.
- Select the target unit and convert.
- Review the square-metre value and multiplier before copying or downloading.
Square units and land-area examples
One square metre is 10,000 square centimetres, because the length scale is squared: 100 × 100. One square foot is 144 square inches. One hectare is 10,000 m², one are is 100 m², and one international acre is 4046.8564224 m² (43,560 international square feet).
Calculation: area × source factor in m² ÷ target factor in m². International factors follow NIST’s measurement tables. The same length multiplier cannot be used directly for a square unit.
| Unit | Square metres per unit |
|---|---|
| Square millimetres (mm²) | 0.000001 |
| Square centimetres (cm²) | 0.0001 |
| Square metres (m²) | 1 |
| Square kilometres (km²) | 1000000 |
| Square inches (in²) | 0.00064516 |
| Square feet (ft²) | 0.09290304 |
| Square yards (yd²) | 0.83612736 |
| Square miles (mi²) | 2589988.110336 |
| Ares (a) | 100 |
| Hectares (ha) | 10000 |
| International acres | 4046.8564224 |
Limits and privacy
Nonnegative source values up to 10¹⁵, with arithmetic underflow rejected. Uses international feet/acres, not historical US survey units or regional land measures with varying definitions. Choose direct area entry or rectangle length and width in a common unit. Each dimension and their resulting square-unit area must be at most 10¹⁵. This does not compute irregular shapes, verify a parcel or assess boundaries.
Definitions are exact, browser arithmetic has finite precision. Display uses up to 12 significant digits and six decimal places or scientific notation for extremes; CSV retains numeric results with possible floating-point rounding. Entered measurements stay in browser memory without uploads, saved values or external conversion requests. Live conversion waits 300 ms. The complete comparison table and CSV cover all eleven supported area units. Result reuse keeps the unrounded result and reverses the conversion; Swap keeps the entered number. Examples, Reset, Swap and result reuse offer one Undo step. Typing discards action history. Reset restores one acre to square metres and clears output. Rectangle CSV retains the original length and width; its source square unit identifies the dimension unit.
Can I use a metres-to-feet length factor for square metres?
Square the length factor. For example, 1 foot = 0.3048 metres but 1 square foot = 0.3048² = 0.09290304 square metres.