Acres to Square Feet Converter
Convert acres to square feet — multiply by 43,560. Results update as you type; exact factors shown.
One acre is 43,560 square feet — see the exact factor, not a rounded rule of thumb.
How the acres to square feet converter works
Areas convert through the square metre. 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 UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common area conversions
| From | To | Units |
|---|---|---|
| 0.1 ac | 4,356 ft² | acres to square feet |
| 0.25 ac | 10,890 ft² | acres to square feet |
| 0.33 ac | 14,374.8 ft² | acres to square feet |
| 0.5 ac | 21,780 ft² | acres to square feet |
| 1 ac | 43,560 ft² | acre to square feet |
| 2 ac | 87,120 ft² | acres to square feet |
| 5 ac | 217,800 ft² | acres to square feet |
| 10 ac | 435,600 ft² | acres to square feet |
| 20 ac | 871,200 ft² | acres to square feet |
| 40 ac | 1,742,400 ft² | acres to square feet |
| 100 ac | 4,356,000 ft² | acres to square feet |
| 640 ac | 27,878,400 ft² | acres to square feet |
Units in this converter and their exact factors
| Unit | Symbol | One unit in square metres |
|---|---|---|
| square millimetre | mm² | 0.000001 square metre |
| square centimetre | cm² | 0.0001 square metre |
| square metre | m² | 1 square metre |
| hectare | ha | 10,000 square metre |
| square kilometre | km² | 1,000,000 square metre |
| square inch | in² | 0.00064516 square metre |
| square foot | ft² | 0.09290304 square metre |
| square yard | yd² | 0.83612736 square metre |
| acre | ac | 4,046.8564224 square metre |
| square mile | mi² | 2,589,988.110336 square metre |
FAQFrequently asked questions about area conversion
How many square feet in an acre?
43,560.
How many square feet is a quarter-acre?
10,890.
How many acres in a square mile?
640 — a survey section.
Is an acre square?
Not necessarily. It is an area, and traditionally it was a long thin strip a furlong by a chain.
How do I measure my land?
Multiply the length by the width in feet, then divide by 43,560.
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 Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.