Free tool
Acres to hectares calculator
To convert acres to hectares, multiply by 0.40468564224. To convert hectares to acres, divide by 0.40468564224, which is the same as multiplying by about 2.4710538. One acre is exactly 4,046.8564224 square metres and one hectare is exactly 10,000 square metres. The calculator below works both ways, in your browser, with no account.
Calculated on this device. Nothing you type is sent anywhere or added to the page address.
The formula
hectares = acres × 0.40468564224
acres = hectares ÷ 0.40468564224
These factors are for the international acre of 43,560 international square feet. NIST Handbook 44 also lists the older US survey acre, which is very slightly larger (about 4,046.8726 square metres). It lists 1 acre as 0.404 685 642 24 hectare exactly, and 1 hectare as 10,000 square metres exactly. The reverse factor, about 2.4710538 acres per hectare, is not a round number, so dividing by the exact acre factor is more precise than multiplying by a rounded one.
Examples
| Acres | Hectares |
|---|---|
| 1 | ≈ 0.4047 |
| 10 | ≈ 4.0469 |
| 40 | ≈ 16.1874 |
| 80 | ≈ 32.3749 |
| 100 | ≈ 40.4686 |
| 160 | ≈ 64.7497 |
| 500 | ≈ 202.3428 |
| 640 | ≈ 258.9988 |
| 1,000 | ≈ 404.6856 |
| 5,000 | ≈ 2,023.4282 |
| Hectares | Acres |
|---|---|
| 1 | ≈ 2.4711 |
| 10 | ≈ 24.7105 |
| 50 | ≈ 123.5527 |
| 100 | ≈ 247.1054 |
| 500 | ≈ 1,235.5269 |
| 1,000 | ≈ 2,471.0538 |
A quarter section of 160 acres is about 64.75 hectares, and a section of 640 acres is about 259 hectares, before road allowances or other deductions.
Precision and rounding
The calculator keeps full precision internally and rounds only what it shows, to four decimal places. A rounded result is marked with “≈”, and the line under it gives the value to 12 significant figures. Copy result copies the rounded number without thousands separators, so it pastes cleanly into a form field. Type numbers with a period for decimals; commas are accepted only as thousands separators. Zero converts to zero; negative or non-numeric input shows an error instead of a result.
A unit converter, not a survey
This tool converts a number from one unit to another. It does not measure land. Legal land areas come from surveys and land titles, and an area worked out from a boundary drawn on a map is an estimate.
Acres and hectares in AgriIntel
In AgriIntel you can enter a farm's size in acres or hectares, and field and activity areas are in acres. Field areas calculated from a drawn boundary use the exact international acre. Stored farm sizes and plan acreage limits use a rounded factor of 2.47105 acres per hectare, which differs from the exact value by about 1.5 parts per million: less than 0.01 acre on a 5,000-acre farm.
Keeping field records on paper first? The farm field record template and the other farm record templates record area in acres. See how AgriIntel keeps farm and field acreage records, or browse the other farm tools.
Sources
- NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement: 1 acre = 0.404 685 642 24 hectare (exactly) and 4 046.856 422 4 square metres; 1 hectare = 10 000 square metres.
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