US Survey Acres to Square Meters (ac (US) to m²)
1 US survey acre equals 4,046.87261 square meters (rounded).
How to convert US survey acres to square meters
To convert US survey acres to square meters, multiply the number of US survey acres by 4,046.87261. The factor is rounded to 10 significant digits. To go the other way, multiply square meters by 0.000247104393 (rounded).
square meters = US survey acres × 4,046.87261
Example: 10 US survey acres = 40,468.7261 square meters.
About these units
US Survey Acre (ac (US))
43,560 square US survey feet (about 4,046.873 m²), slightly larger than the international acre. Used in US land records until 2022.
Two acres existed side by side in the United States for decades, separated by a tiny difference in the definition of the foot. Both contain 43,560 square feet, but the international acre uses the foot fixed in 1959 from a yard of exactly 0.9144 meter, giving 4,046.8564224 square meters. The survey acre keeps the older relation set by the 1893 Mendenhall Order, in which one meter is exactly 39.37 inches, giving about 4,046.873 square meters.
The gap is only about 0.016 square meter, roughly 160 square centimeters, but across a large state it adds up to real discrepancies, which is why surveyors held on to the old figure for land records. In October 2019 the National Geodetic Survey and NIST announced that the temporary continued use of the survey foot, mile and acre would end at the close of 2022, and the international units are meant to replace them. The acre itself began as the land a farmer with oxen could plough in a day, and its name comes from an Old Norse word for cultivated land.
1 US survey acre = 4,046.87261 square meters (approximately).
Sources: Wikipedia: Acre; NIST SP 811 Appendix B.8 (conversion factors)
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 US survey acres (reverse)
- US survey acres to square kilometers
- US survey acres to hectares
- US survey acres to square inches
- US survey acres to square feet
- US survey acres to square yards
- US survey acres to acres
- US survey acres to square miles
- Square kilometers to square meters
- Hectares to square meters
- Square inches 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
See all area units.