square inch (in²)
1 square inch = 0.00064516 square metres
What is square inch?
A square inch is a unit of area in imperial and US customary systems equal to 1/144 of a square foot. It is used for measuring small surfaces, printed circuit boards, and product specifications in imperial-based industries.
Notes: Imperial/USCS unit
Real-world uses
Square inches are used for pressure measurements (psi = pounds per square inch), display pixel density (pixels per square inch), and small-area calculations for labels, stamps, and PCB layouts in the US. Cooking pan sizes are sometimes described in square inches.
History
The square inch derives from the inch, which was standardized internationally in 1959 as exactly 25.4 mm. It has long been used in American and British engineering for specifying small areas, cross-sections, and pressure measurements.
Common mistakes
Confusing square inches with cubic inches (a volume unit used for engine displacement). Also, forgetting that 1 ft² = 144 in² (12 × 12), not 12 in².
When is this conversion used?
Converting between square inch and square metre is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.
How to convert square inch to square metre
To convert square inch to square metre, multiply the value by 0.00064516.
Conversion formula (from base unit)
x * 0.00064516
Measurement standards
The square metre is the SI derived unit of area. The hectare (10,000 m²) is accepted for use with the SI by the BIPM, particularly for land measurement, though it is not an SI unit itself.
Did you know?
Vatican City, the world's smallest independent state, covers just 0.44 km² (about 109 acres) — smaller than many golf courses. By contrast, Russia spans over 17.1 million km², nearly 39 million times larger.
| square inches | square metres |
|---|---|
| 0.1 | 0.00006452 |
| 0.5 | 0.00032258 |
| 1 | 0.00064516 |
| 2 | 0.00129032 |
| 5 | 0.0032258 |
| 10 | 0.0064516 |
| 25 | 0.016129 |
| 50 | 0.032258 |
| 100 | 0.064516 |
| 250 | 0.16129 |
| 500 | 0.32258 |
| 1,000 | 0.64516 |
Common values
| square inches | square metres | |
|---|---|---|
| A4 paper | 96.1001922 square inches | 0.062 square metres |
| Parking space | 19,375.03875008 square inches | 12.5 square metres |
| Tennis court | 404,349.30869862 square inches | 260.87 square metres |
| Football field (soccer) | 11,067,022.13404427 square inches | 7,140 square metres |
| Central Park, NYC | 5.285511e+09 square inches | 3,410,000 square metres |
Full square inch conversion table
| Unit | Value | Factor |
|---|---|---|
| square metre | 1 in² = 0.00064516 m² | × 0.00064516 |
| square kilometre | 1 in² = 6.451600e-10 km² | × 6.451600e-10 |
| square foot | 1 in² = 0.00694444 ft² | × 0.00694444 |
| square mile | 1 in² = 2.490977e-10 mi² | × 2.490977e-10 |
| acre | 1 in² = 1.594225e-07 ac | × 1.594225e-07 |
| hectare | 1 in² = 6.451600e-08 ha | × 6.451600e-08 |
| square centimetre | 1 in² = 6.4516 cm² | × 6.4516 |
| square yard | 1 in² = 0.0007716 yd² | × 0.0007716 |
| are | 1 in² = 0.00000645 a | × 0.00000645 |