10 ac to ha
- Acres (ac)
- 10 ac
- Hectares
- 4.0468564224 ha
Checked against: Exact-fraction computation from the legal unit definitions
Acres to hectares converter
Convert acres to hectares (acres to hectares) with the exact factor, a conversion chart and worked steps.
By AdminDrafted with AI writing toolsUpdated Checked examples: 3
Hectares
ha
Hectares: 4.0468564224 ha
- Conversion
- 10 ac = 4.0468564224 ha
- 1 ha in acres
- 2.471053815ac
10 ac is about 4.0468564224 ha. In the other direction, 1 ha ≈ 2.47105381 ac.
Acres to hectares
Acres to hectares chart
| Acres | Hectares |
|---|---|
| 0.1 | 0.0405 |
| 0.25 | 0.1012 |
| 0.5 | 0.2023 |
| 1 | 0.4047 |
| 2 | 0.8094 |
| 5 | 2.0234 |
| 10 | 4.0469 |
| 20 | 8.0937 |
| 40 | 16.1874 |
| 100 | 40.4686 |
| 640 | 258.9988 |
How it's calculated S
Conversion factor
Exact by definition.
Multiply
About the acres to hectares converter
To convert acres to hectares, multiply by 0.4046856422; to convert back, multiply by 2.4710538147. For example, 10 ac is about 4.046856 ha. Displayed factors and results may be rounded.
An acreage describes land area, not its shape or boundary length. The same acreage can have many different perimeters. Convert the recorded parcel area when comparing land listings, and consult the survey itself for legal boundaries or historical measurement conventions.
International definition of acre: 1 acre = 43,560 ft² = 4,046.8564224 m². These values are exact.
Both units are defined exactly. Calculations use 50 significant digits and round only for display.
How to convert acres to hectares
Multiply acres by 0.40468564224, or 0.4047 for most uses: ha = acres × 0.4047. So 1 acre = 0.4047 ha, 10 acres = 4.047 ha and 100 acres = 40.47 ha. The hectare figure is always smaller, about 40% of the acreage, because a hectare is the bigger unit.
Where 0.40468564224 comes from
Acres (ac) are 43,560 sq ft. With the international foot of exactly 0.3048 m, that is 4,046.8564224 m². A hectare is 10,000 m², so one acre is exactly 0.40468564224 ha.
Acres to hectares chart
| Acres (ac) | Hectares (ha) |
|---|---|
| 0.1 | 0.040468564224 |
| 0.5 | 0.20234282112 |
| 1 | 0.40468564224 |
| 2 | 0.80937128448 |
| 2.5 | 1.0117141056 |
| 5 | 2.0234282112 |
| 10 | 4.0468564224 |
| 20 | 8.0937128448 |
| 50 | 20.234282112 |
| 100 | 40.468564224 |
US land sections in hectares
US farmland is often described by Public Land Survey divisions. A section is 640 acres, or 259.0 ha (2.59 km²); a quarter section is 160 acres (64.75 ha), and a quarter-quarter section is 40 acres (16.19 ha).
Converting prices and rates per acre
Anything quoted per acre converts the other way: multiply by 2.471, the number of acres in a hectare. Land at $5,000 per acre costs $12,355 per hectare, and 100 lb of seed per acre is 247.1 lb, or 112.1 kg, per hectare.
Multiplying the rate by 0.4047 instead gives 40.5 lb per hectare, about a sixth of the true rate.
Quick estimate
Multiply by 0.4, which runs 1.2% low: 25 acres ≈ 10 ha, against an exact 10.12 ha. A handy anchor is that 2.5 acres is just over a hectare (1.012 ha), so every 5 acres is about 2 ha.
Acres in square meters and square kilometers
For a building plot, square meters can be more useful than hectares: 1 acre is 4,046.86 m², so a half-acre plot is 2,023.4 m². For large holdings, divide the hectare figure by 100 to get km²: 1,000 acres is 404.69 ha, or 4.05 km².
US survey acres in older records
Older US land records may use the US survey foot, which NIST retired at the end of 2022. A survey acre is 4,046.873 m², 0.016 m² more than the international acre, which matters only for precise survey work.
Hectares back to acres
Multiply hectares by 2.471, or use the hectares to acres converter. The acres to square feet converter gives lot sizes in square feet, and the area converter covers square kilometers and square miles.
Worked examples
1 ac to ha
- Acres (ac)
- 1 ac
- Hectares
- 0.40468564224 ha
Checked against: Exact-fraction computation from the legal unit definitions
100 ac to ha
- Acres (ac)
- 100 ac
- Hectares
- 40.468564224 ha
Checked against: Exact-fraction computation from the legal unit definitions
Questions
How many hectares are in one acre?
1 ac is about 0.4046856422 ha. International definition of acre: 1 acre = 43,560 ft² = 4,046.8564224 m². These values are exact.
How do I convert acres to hectares?
Multiply by 0.4046856422: 10 ac × 0.4046856422 ≈ 4.046856 ha. To convert back, divide by the same factor. The factor shown may be rounded.
How can I estimate acres in hectares without a calculator?
Multiply by 0.4. This is 1.2% below the exact factor (about 0.4046856422), so 10 ac comes out as 4 ha instead of 4.0469 ha.
About this calculator
Sources
Checked against references
This calculator includes 3 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.