Square Feet to Acres Converter
ConversionsPick the unit you start with: square feet, acres, square meters, hectares or a lot given by length and width in feet. You get acres or square feet, the other area units and the side of a square lot of that size.
Step by step
10,000 / 43,560 = 0.2296
- An acre is 43,560 square feet, so divide: 10,000 / 43,560 = 0.2296 acres.
- In metric, multiply by 0.09290304 m² per square foot: 10,000 × 0.09290304 = 929.03 m², which is 0.0929 ha.
- In square yards, divide by 9: 10,000 / 9 = 1,111.11 sq yd.
Once every entry is valid, you’ll see each step of the calculation here.
Formula
- sq ft
- area in square feet
- acres
- area in acres
- 43,560
- square feet in one acre, exact by definition
- 0.09290304
- square meters in one square foot, exact: 0.3048 m × 0.3048 m
- length, width
- the two sides of a rectangular lot, both in feet
How it works
One acre is exactly 43,560 square feet. The acre goes back to the strip a team of oxen could plow in a day and was later fixed as a furlong (660 ft) by a chain (66 ft). To convert square feet to acres, divide by 43,560: 10,000 sq ft is 0.2296 acre, and 20,000 sq ft is 0.4591 acre. To convert acres to square feet, multiply: a quarter acre is 10,890 sq ft, half an acre is 21,780 sq ft and 5 acres are 217,800 sq ft.
The lot size mode is an acreage calculator for a rectangle: multiply the length by the width in feet to get square feet, then divide by 43,560. A lot of 200 ft by 200 ft is 40,000 sq ft, which is 0.918 acre, so it is not quite an acre. A square acre measures about 208.71 ft on each side. For irregular lots, split the shape into rectangles and triangles and add the areas, or use the area from your survey or deed.
Metric areas are exact too: a square foot is 0.09290304 m² because the foot is exactly 0.3048 m, so an acre is 4,046.8564224 m² and a hectare (10,000 m²) is 2.4711 acres. A square mile is 640 acres. A square yard is 9 square feet, and an acre is 4,840 square yards. To convert lengths rather than areas, see the cm to feet converter, which also turns meters into feet.
The formula
The factors are exact by definition, so only the displayed digits are rounded. The result for a lot assumes a rectangle with square corners. A parcel with slanted sides, a curved boundary or a slope measured along the ground needs the surveyed area instead.
Land records that use the older US survey foot differ from the international foot by about 4 parts per million in area, which changes an acre by roughly 0.016 m². That is invisible at any size you would build on, so this page uses the international foot.
Example
How many acres is a 10,000 square foot lot?
- Divide by the 43,560 square feet in an acre: 10,000 / 43,560 = 0.2296 acres.
- So 10,000 sq ft is a little under a quarter acre (a quarter acre is 10,890 sq ft), or 929.03 m² in metric.
10,000 sq ft = 0.2296 acres, or 929.03 m² and 0.0929 ha.
Load this example into the calculatorFrequently asked questions
How many square feet are in an acre?
There are 43,560 square feet in one acre. Half an acre is 21,780 sq ft, a quarter acre is 10,890 sq ft, 2 acres are 87,120 sq ft and 5 acres are 217,800 sq ft.
How long is each side of a one-acre square lot?
A square lot of one acre measures about 208.71 feet on each side, because the square root of 43,560 is 208.71. A lot of 200 ft by 208.71 ft is about 0.96 acre, and 100 ft by 435.6 ft is exactly one acre.
What is 10,000 sq ft vs. acres?
10,000 square feet is 0.2296 acre, a little less than a quarter acre. The other way, one acre is 4.356 times larger than 10,000 sq ft, and 20,000 sq ft is 0.4591 acre.
Is 200 ft by 200 ft considered an acre?
No. 200 ft × 200 ft is 40,000 square feet, which is 0.918 acre. To make a full acre with a 200 ft side, the other side must be 217.8 ft long. A square acre is about 208.71 ft by 208.71 ft.
How many acres do you need for a 100,000 sq ft building?
A building floor area of 100,000 sq ft is 2.30 acres if it fits on one floor. The land is larger: with a floor area ratio of 0.5, which means floors add up to half the lot, the parcel must be 200,000 sq ft or 4.59 acres. Parking, setbacks and drainage are extra, so check the local zoning rules.
How do you calculate acreage?
For a rectangular lot, multiply length by width in feet and divide by 43,560. A lot of 150 ft by 300 ft is 45,000 sq ft, which is 1.033 acres. For other shapes, split the lot into rectangles and triangles and add the pieces, or use the surveyed area on your deed.
How many acres is a hectare, and how many square feet is a square mile?
One hectare is 2.471 acres and one acre is 0.4047 hectare. A square mile is 640 acres, which is 27,878,400 square feet.
- NIST Guide to the SI, Appendix B: Conversion Factors (National Institute of Standards and Technology)
- Approximate Conversions from U.S. Customary Measures to Metric (National Institute of Standards and Technology)
- Acre (Wikipedia)