Acres to Square Metres Converter
Convert acres to square metres — an acre is 4,046.86 m². Results update as you type; exact factors shown.
One acre is 4,046.8564 square metres — see the exact factor, not a rounded rule of thumb.
How the acres to square metres 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.
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
Common area conversions
| From | To | Units |
|---|---|---|
| 0.1 ac | 404.6856 m² | acres to square metres |
| 0.25 ac | 1,011.7141 m² | acres to square metres |
| 0.5 ac | 2,023.4282 m² | acres to square metres |
| 1 ac | 4,046.8564 m² | acre to square metres |
| 1.5 ac | 6,070.2846 m² | acres to square metres |
| 2 ac | 8,093.7128 m² | acres to square metres |
| 2.5 ac | 10,117.1411 m² | acres to square metres |
| 5 ac | 20,234.2821 m² | acres to square metres |
| 10 ac | 40,468.5642 m² | acres to square metres |
| 20 ac | 80,937.1284 m² | acres to square metres |
| 50 ac | 202,342.8211 m² | acres to square metres |
| 100 ac | 404,685.6422 m² | acres to square metres |
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 metres in an acre?
4,046.86 m².
How many acres in a hectare?
2.471.
Where does the acre come from?
The area a yoke of oxen could plough in a day — one furlong by one chain, which is 4,840 square yards.
What is half an acre in m²?
2,023 m².
Is an acre a square?
No — it is an area, historically a long thin strip. Any shape of 4,046.86 m² is an acre.
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 Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.