Square Inches to Ares (in² to a)

1 square inch equals 0.0000064516 ares exactly.

1 square inch = 0.0000064516 ares

How to convert square inches to ares

To convert square inches to ares, multiply the number of square inches by 0.0000064516. This factor is exact. To go the other way, multiply ares by 155,000.31 (rounded).

ares = square inches × 0.0000064516

Example: 10 square inches = 0.000064516 ares.

About these units

Square Inch (in²)

US & ImperialCurrent unit

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

Are (a)

Metric (SI)Traditional unit (still used in some regions)

100 square meters, a square 10 m on a side. Mostly replaced by the hectare (100 ares).

Latin area, meaning an open piece of ground, gave French the word are, the base land unit of the metric system. A French law of 1795 defined it as 100 square meters, a square ten meters on each side, and the hectare was then built as 100 ares, which is why that familiar unit carries the "hecto-" prefix.

The are itself never made it into the modern SI when the system was rationalised in 1960, and the hectare took over for fields, forests and planning. The are survives mostly as a convenience for small plots such as building lots and gardens, and in everyday talk in parts of continental Europe. NIST lists it as exactly 100 square meters, so the figure used here is firm, and 100 ares make one hectare. The hectare is about 2.47 acres, so an are is roughly a fortieth of an acre.

1 are = 100 square meters (exactly).

Sources: Wikipedia: Hectare; NIST SP 811, Appendix B.8 conversion factors

Related conversions

See all area units.