How to Convert Square inches to Square metres (sq in to m²)
Area conversions are everyday maths in Singapore property: HDB flats are listed in square metres while condo listings and PSF prices use square feet. This guide shows how to convert square inches into square metres by hand, with examples and a quick-reference table.
The conversion
To convert square inches to square metres, multiply the value by 0.00064516. To go the other way, divide by the same number (or multiply by 1,550.0031000062). Because the factor is tiny, scientific notation keeps the numbers manageable.
Square metres = square inches × 0.00064516
Worked examples
- 3 sq in = 0.001935 m²
- 12.5 sq in = 0.008065 m²
- 75 sq in = 0.048387 m²
Square inches to Square metres table
| Square inches | Square metres |
|---|---|
| 1 sq in | 0.000645 m² |
| 2 sq in | 0.00129 m² |
| 5 sq in | 0.003226 m² |
| 10 sq in | 0.006452 m² |
| 20 sq in | 0.012903 m² |
| 25 sq in | 0.016129 m² |
| 50 sq in | 0.032258 m² |
| 100 sq in | 0.064516 m² |
| 250 sq in | 0.16129 m² |
| 500 sq in | 0.32258 m² |
| 1,000 sq in | 0.64516 m² |
Common questions
Is sq in to m² exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Square metres to Square inches converter.
Mistakes to avoid
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Background
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
For any value, use the Square inches to Square metres Converter or browse all area converters.
Run your own numbers: Square inches to Square metres Converter