Square Inches to Square Meters (in² to m²)
1 square inch equals 0.00064516 square meters exactly.
How to convert square inches to square meters
To convert square inches to square meters, multiply the number of square inches by 0.00064516. This factor is exact. To go the other way, multiply square meters by 1,550.0031 (rounded).
square meters = square inches × 0.00064516
Example: 10 square inches = 0.0064516 square meters.
About these units
Square Inch (in²)
A square one inch on a side, exactly 6.4516 cm². Used for small parts and for pressure (pounds per square inch).
Latin uncia, one twelfth, gave English the inch, which Old English borrowed as ynce. A statute of Edward II in 1324 defined it as three barleycorns, dry and round, set end to end, and the barleycorn remained the base for centuries after 1066. The modern square inch rests on a 20th-century agreement: the United States adopted a yard of exactly 0.9144 meter on 1 July 1959, the United Kingdom followed effective 1 January 1964, and the inch became exactly 25.4 mm.
Squaring that gives exactly 6.4516 cm² for one square inch, and one square meter is about 1,550 of them. Its best-known descendant is the pound per square inch, psi, the pressure unit still used for American tires and air tanks: atmospheric pressure at sea level is about 14.7 psi, a car tire is typically inflated to around 32 psi above the surrounding air, and one psi is about 6.895 kilopascals. The square inch itself is common in the US and UK for small parts and printed material.
1 square inch = 0.00064516 square meters (exactly).
Sources: Wikipedia: Square inch; Wikipedia: Inch; Wikipedia: Pounds per square inch
Square Meter (m²)
The SI unit of area: a square one meter on each side. Used for floor areas and property sizes in most of the world.
Squaring the meter was built into the metric system from the start. The French law of 18 Germinal, Year III (7 April 1795) defined the are, the land unit that gave the hectare its name, as exactly 100 square meters, so the square meter was already the foundation of metric land measure. Nobody is credited with inventing it as a separate unit. It is simply the area of a square one meter on each side, and any SI prefix that works for the meter works for it, with the prefix squared along with the unit.
That squaring catches people out: a square kilometer is one million square meters, not one thousand. Since 1983 the meter has been defined through the speed of light, so the square meter is tied to a constant of nature as well as to the second. A hectare, about the area of Trafalgar Square in London, is 10,000 square meters. In everyday terms one square meter is about 10.76 square feet. Unicode has a compatibility character for it, but the recommended way to write it is the plain superscript two: m².
The square meter is the reference unit for area on this site.
Sources: Wikipedia: Square metre; Wikipedia: Are (unit); NIST: the meter and the SI redefinition
Related conversions
- Square meters to square inches (reverse)
- Square inches to square kilometers
- Square inches to hectares
- Square inches to square feet
- Square inches to square yards
- Square inches to acres
- Square inches to square miles
- Square inches to square centimeters
- Square inches to square millimeters
- Square inches to tsubo
- Square inches to pyeong
- Square inches to rai (Thai)
- Square inches to barns
- Square kilometers to square meters
- Hectares to square meters
- Square feet to square meters
- Square yards to square meters
- Acres to square meters
- Square miles to square meters
- Square centimeters to square meters
- Square millimeters to square meters
- Tsubo to square meters
- Pyeong to square meters
- Rai (Thai) to square meters
- Barns to square meters
See all area units.