Convert acres to hectares instantly. Enter a value below, or use the formula and reference table further down the page.
In practice
Acres to hectares is the land-area conversion between US/UK and metric measures. One acre is 0.404686 hectares, so a 10-acre plot is 4.05 hectares. A hectare is a square 100 m on a side (10,000 m²), a little under two and a half acres (2.47). It is used in agriculture and property listings worldwide, so a 100-hectare farm sounds large but is about 247 acres. The acre itself was defined historically as the area a team of oxen could plough in a day.
How to convert acres to hectares
Multiply the value by 0.4046856422.
ha = ac × 0.4046856422Example: 10 ac = 4.0469 ha.
Acres to Hectares conversion table
| Acres (ac) | Hectares (ha) |
|---|---|
| 1 ac | 0.4047 ha |
| 2 ac | 0.8094 ha |
| 3 ac | 1.2141 ha |
| 4 ac | 1.6187 ha |
| 5 ac | 2.0234 ha |
| 10 ac | 4.0469 ha |
| 15 ac | 6.0703 ha |
| 20 ac | 8.0937 ha |
| 25 ac | 10.1171 ha |
| 50 ac | 20.2343 ha |
| 100 ac | 40.4686 ha |
Frequently asked questions
How many hectares is 1 acre?
1 acre equals 0.4047 hectares.
What is the formula to convert ac to ha?
To convert ac to ha, multiply the value by 0.4046856422. The full formula is: ha = ac × 0.4046856422.
How do I convert hectares back to acres?
Use the same calculator above and type your value into the hectares field instead — it converts in both directions. Or use the reverse formula: ac = ha ÷ 0.4046856422.
Is the ac to ha conversion exact?
The conversion factor used here (0.4046856422) is the standard internationally defined value. Results on this page are rounded to four decimal places for readability.