Acres to Hectares Converter
One acre equals approximately 0.404686 hectares. The exact factor is 0.40468564224, derived from the exact definitions: 1 acre = 4,046.8564224 m² and 1 hectare = 10,000 m².
Formula
hectares = acres × 0.40468564224
Reverse:
acres = hectares × 2.471053814671653
Formula variables
- acres — area in international acres (ac).
- hectares — equivalent area in hectares (ha).
- 0.40468564224 — exact hectares per acre. Derived from 4,046.8564224 m² per acre ÷ 10,000 m² per hectare.
Worked Examples
Example 1: 1 acre to hectares
- Start: 1 acre = 4,046.8564224 m².
- 1 hectare = 10,000 m².
- Divide: 4,046.8564224 ÷ 10,000 = 0.40468564224.
- Result: 1 acre ≈ 0.404686 hectares.
Example 2: 10 acres to hectares
- Start: 10 acres.
- Multiply: 10 × 0.40468564224 = 4.0468564224.
- Result: 10 acres ≈ 4.0469 hectares. This is a small farm or large residential property.
Example 3: 640 acres to hectares
- Start: 640 acres (1 square mile).
- Multiply: 640 × 0.40468564224 = 259.0 (exactly 259.0).
- Result: 640 acres = 259.0 hectares (approximately, since the exact value is 258.99881103...).
Common Conversion Table
| Acres (ac) | Hectares (ha) | Approximate size |
|---|---|---|
| 0.25 | 0.101171 | Large house plot |
| 0.5 | 0.202343 | Smallholding |
| 1 | 0.404686 | Standard acre |
| 2 | 0.809371 | Small farm |
| 5 | 2.023428 | Hobby farm |
| 10 | 4.046856 | Small farm |
| 25 | 10.117141 | Farm |
| 50 | 20.234282 | Large farm |
| 100 | 40.468564 | Large farm |
| 640 | 258.998811 | 1 square mile |
Real-World Uses
- Agriculture: Farm sizes in the US and UK are typically quoted in acres; internationally in hectares.
- Real estate: Land parcels in the US are often advertised in acres; in Europe and most of the world, in hectares.
- Forestry: Timberland area is measured in both units depending on the operator's country.
- Environmental science: Protected areas, conservation easements, and land-use studies often use hectares for consistency in international reporting.
- Government planning: Zoning and land-use regulations may specify minimum lot sizes in acres (US) or hectares (elsewhere).
Unit Definitions
Acre (ac)
A unit of area equal to exactly 4,046.8564224 square meters, or 43,560 square feet, or 1/640 of a square mile. Originally defined as the area a yoke of oxen could plow in one day. It is a customary and imperial unit used primarily in the US and UK.
Hectare (ha)
A metric unit of area equal to exactly 10,000 square meters (100 m × 100 m). It is not an SI unit but is accepted for use with SI. It is the standard unit for land measurement in most of the world outside the US and UK.
Accuracy and Rounding
Because both units have exact definitions, the conversion factor is exact. In practice, land measurement is often imprecise at the survey level, so displayed conversions typically round to 2–4 decimal places.
Related Converters
- Hectares to Acres — reverse conversion
- Square Feet to Square Meters
- Square Miles to Square Kilometers
- All Area Converters
Frequently Asked Questions
How many hectares in an acre?
One acre equals approximately 0.404686 hectares. The exact factor is 0.40468564224, derived from the exact SI definitions of both units.
Is an acre bigger than a hectare?
No. One hectare is larger than one acre. One hectare = 10,000 m²; one acre = 4,046.8564224 m². So one hectare is about 2.471 acres.
How do you convert acres to hectares?
Multiply the acre value by 0.40468564224. For example, 10 acres × 0.40468564224 = 4.0469 hectares.
How many acres in a hectare?
One hectare equals approximately 2.4710538 acres.
What is the size of a hectare in familiar terms?
A hectare is 10,000 square meters — roughly the size of an international rugby pitch (which is 100 m × 70 m = 7,000 m²), or about 1.5 international football (soccer) pitches. It is a square 100 m on each side.