Acres to Square Feet Converter
43,560 square feet to an acre, and where that odd number comes from.
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Free · No sign-up · Updates as you type · Exact factor, per NIST
- 0.1 ac4,356 ft²405 m²
- 0.25 ac10,890 ft²1,012 m²
- 0.5 ac21,780 ft²2,023 m²
- 1 ac43,560 ft²4,047 m²
- 2 ac87,120 ft²8,094 m²
- 5 ac217,800 ft²20,234 m²
- 10 ac435,600 ft²40,469 m²
- 20 ac871,200 ft²80,937 m²
- 40 ac1,742,400 ft²161,874 m²
Where 43,560 comes from
The traditional account is that an acre was the area a team of oxen could plow in a day, standardized as a long thin strip one chain wide by one furlong long. That origin story is widely repeated and hard to source firmly, so treat it as folk etymology. What is solid is the geometry: a chain is 66 feet, a furlong is 660 feet, and 66 × 660 is exactly 43,560. The awkward number is a survival of that shape rather than an arbitrary choice.
Conversion table
| Acres | Square feet | Square meters | Hectares |
|---|---|---|---|
| 0.1 ac | 4,356 | 405 | 0.0405 |
| 0.25 ac | 10,890 | 1,012 | 0.1012 |
| 0.5 ac | 21,780 | 2,023 | 0.2023 |
| 1 ac | 43,560 | 4,047 | 0.4047 |
| 2 ac | 87,120 | 8,094 | 0.8094 |
| 5 ac | 217,800 | 20,234 | 2.0234 |
| 10 ac | 435,600 | 40,469 | 4.0469 |
| 25 ac | 1,089,000 | 101,171 | 10.1171 |
| 50 ac | 2,178,000 | 202,343 | 20.2343 |
| 100 ac | 4,356,000 | 404,686 | 40.4686 |
Common questions
How many square feet are in an acre?
43,560 exactly. The figure comes from the acre's historic definition as one chain by one furlong, which is 66 feet by 660 feet.
How big is an acre?
About 209 feet square, or roughly 90 percent of an American football field excluding the end zones.
How do I convert square feet to acres?
Divide by 43,560. A 10,000 square foot lot is about 0.23 acres.
Is a US acre the same as an international acre?
Now, yes. The US survey acre was defined via the US survey foot and differed very slightly. That foot was deprecated on 31 December 2022, and the same notice redefined the acre on the international foot. Since 1 January 2023 there is one acre in official US use.
Related converters and guides
Sources
- U.S. Survey Foot: Frequently Asked Questions. National Institute of Standards and Technology. Source for the 31 December 2022 deprecation, the obsolete status from 1 January 2023, and the retention of the survey foot for legacy state plane coordinate systems only.
- NIST Guide to the SI, Appendix B: Conversion Factors. National Institute of Standards and Technology. Source for every conversion factor on this page, and for which factors are exact rather than rounded.