Why Convert Acres to Hectares?
Converting between acres (ac) and hectares (ha) is one of the most common area conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert ac to ha saves time and prevents errors.
Area conversions between ac and ha are critical in real estate, agriculture, and urban planning. When buying property internationally, apartment sizes are quoted in square meters in most countries but square feet in the US. Agricultural land in China uses mu (亩), while Western countries use hectares or acres. Understanding area conversion helps compare real estate prices across different markets accurately.
How to Convert Acres to Hectares
To convert acres to hectares, use the following formula:
ha = ac × 0.4046856422
Example: 1 ac = 0.4046856422 ha
For example, 5 ac = 2.023428211 ha, 10 ac = 4.046856422 ha, and 100 ac = 40.46856422 ha. Our calculator above performs this conversion instantly with full precision — no rounding errors.
Common Use Cases
- Typical suburban lot (large): 1 ac = 0.4046856422 ha
- Small US ranch: 40 ac = 16.18742569 ha
- One square mile (section of land): 640 ac = 258.998811 ha
- Rural residential property: 5 ac = 2.023428211 ha
Common Mistakes to Avoid
- Square vs linear: When converting area, the factor is squared. If 1 m = 3.281 ft, then 1 m² = 10.764 ft² (3.281²), not 3.281 ft².
- Hectare vs acre precision: 1 hectare = 2.471 acres. Many people round to 2.5, which introduces 1.2% error — significant for land transactions.
- Regional units: Asian countries use unique area units (畝/mu in China, 坪/pyeong in Korea/Taiwan). Don't assume universal standards.
Pro Tips
- Memorize the factor: 1 ac = 0.4046856422 ha. For quick mental math, remember this base conversion.
- Quick reference: 5 ac = 2.023428211 ha · 10 ac = 4.046856422 ha · 25 ac = 10.11714106 ha · 50 ac = 20.23428211 ha · 100 ac = 40.46856422 ha
- Bookmark this page: Save this converter for instant access. It works offline once loaded — no internet needed.
Acres to Hectares Conversion Table
| ac | ha |
|---|---|
| 0.01 ac | 0.004046856422 ha |
| 0.1 ac | 0.04046856422 ha |
| 0.5 ac | 0.2023428211 ha |
| 1 ac | 0.4046856422 ha |
| 2 ac | 0.8093712845 ha |
| 5 ac | 2.023428211 ha |
| 10 ac | 4.046856422 ha |
| 20 ac | 8.093712845 ha |
| 50 ac | 20.23428211 ha |
| 100 ac | 40.46856422 ha |
| 500 ac | 202.3428211 ha |
| 1000 ac | 404.6856422 ha |
All values in this table are mathematically exact per NIST SP 811.