Square Feet to Acres Converter
Convert square feet to acres — 43,560 square feet to the acre. Results update as you type; exact factors shown.
One square foot is 0 acres — see the exact factor, not a rounded rule of thumb.
How the square feet to acres converter works
Areas convert through the square meter. Because the inch is exactly 25.4 mm, a square foot is exactly 0.09290304 m², an acre (43,560 square feet) is exactly 4,046.8564224 m² and a square mile (640 acres) is 2,589,988.110336 m². A hectare is 10,000 m² by definition.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common area conversions
| From | To | Units |
|---|---|---|
| 1,000 ft² | 0.023 ac | square feet to acres |
| 5,000 ft² | 0.1148 ac | square feet to acres |
| 10,000 ft² | 0.2296 ac | square feet to acres |
| 21,780 ft² | 0.5 ac | square feet to acres |
| 43,560 ft² | 1 ac | square feet to acres |
| 87,120 ft² | 2 ac | square feet to acres |
| 100,000 ft² | 2.2957 ac | square feet to acres |
| 200,000 ft² | 4.5914 ac | square feet to acres |
| 435,600 ft² | 10 ac | square feet to acres |
| 500,000 ft² | 11.4784 ac | square feet to acres |
| 1,000,000 ft² | 22.9568 ac | square feet to acres |
| 2,000,000 ft² | 45.9137 ac | square feet to acres |
Units in this converter and their exact factors
| Unit | Symbol | One unit in square meters |
|---|---|---|
| square millimeter | mm² | 0.000001 square meter |
| square centimeter | cm² | 0.0001 square meter |
| square meter | m² | 1 square meter |
| hectare | ha | 10,000 square meter |
| square kilometer | km² | 1,000,000 square meter |
| square inch | in² | 0.00064516 square meter |
| square foot | ft² | 0.09290304 square meter |
| square yard | yd² | 0.83612736 square meter |
| acre | ac | 4,046.8564224 square meter |
| square mile | mi² | 2,589,988.110336 square meter |
FAQFrequently asked questions about area conversion
How many square feet in an acre?
43,560 exactly.
How big is that?
About the size of an American football field without the end zones.
Where did 43,560 come from?
An acre was one furlong (660 ft) by one chain (66 ft), which multiplies to 43,560.
How many acres is a typical suburban block?
Often a quarter to a third of an acre.
What is an acre in square meters?
4,046.86 m².
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.