Acre to Hectare Converter
Convert acres to hectares and hectares to acres, using the exact international definition.
About the Acre to Hectare Converter
Farm, forest and property sizes are quoted in acres in the US, the UK and much of South Asia, and in hectares almost everywhere else and in most official statistics. Choose the direction and enter a value.
One acre is exactly 4,046.8564224 m², so 0.40468564224 hectares; the factor is exact because the acre has been defined from the international foot since 1959. One hectare is 10,000 m² (100 m × 100 m), about 2.471 acres.
The formula
ha = acres × 0.40468564224
- ha
- hectares (10,000 m²)
- 0.40468564224
- hectares in one acre, exact
Quick reference
| Acres | Hectares |
|---|---|
| 1 | 0.4047 |
| 2.5 | 1.0117 |
| 5 | 2.0234 |
| 10 | 4.0469 |
| 100 | 40.4686 |
| 2.4711 | 1 |
| 12.3553 | 5 |
| 24.7105 | 10 |
Worked example
A 25-acre farm in hectares
- 25 × 0.40468564224 = 10.1171 ha
- Back again: 10.1171 ha × 2.4710538 = 25 acres
Questions people ask
Which countries use hectares?
Most of the world for land, including India in official records alongside acres.
How many acres is a square mile?
640 acres, which is 258.999 hectares.
Is a hectare bigger than an acre?
Yes, about two and a half times bigger: 1 ha = 2.4711 acres.
Is the US survey acre different?
Very slightly: the old US survey acre is about 4,046.873 m², 2 parts per million larger. The US retired the survey foot in 2023, so the international acre used here is the standard.