Convert Square Miles to Hectares
Square miles to hectares is the conversion you need whenever land is measured in square miles but the rest of the world around you works in hectares. One square mile is exactly 258.9988110336 hectares, so the number gets larger when you switch from square miles to hectares.
Square miles to Hectares conversion table
| Square miles (mi²) | Hectares (ha) |
|---|---|
| 1 | 258.998811 |
| 2 | 517.997622 |
| 3 | 776.996433 |
| 5 | 1,294.994055 |
| 10 | 2,589.98811 |
| 20 | 5,179.976221 |
| 50 | 12,949.940552 |
| 100 | 25,899.881103 |
| 500 | 129,499.405517 |
| 1,000 | 258,998.811034 |
The formula
To convert square miles to hectares, multiply the number of square miles by 258.9988110336:
hectares = square miles × 258.9988110336
A worked example
Say you have 10 square miles of land and want it in hectares:
10 × 258.9988110336 = 2,589.99 hectares
So 10 square miles works out to just under 2,590 hectares.
Why the number is exact
A mile is defined as exactly 1609.344 meters, which makes a square mile exactly 2,589,988.110336 square meters. A hectare is defined as exactly 10,000 square meters, so dividing one by the other gives exactly 258.9988110336 hectares per square mile. Every step is exact, so the conversion is too.
When you'll use it
Comparing US land areas with countries that measure in hectares, reading international property or agricultural listings, and filling in planning or land-use paperwork where hectares are the standard unit.
Frequently asked questions
How many hectares are in a square mile?
Exactly 258.9988110336 hectares. It's an exact figure, not a rounded one, because a mile is defined as exactly 1609.344 meters and a hectare is just 10,000 square meters.
Is the square miles to hectares conversion exact?
Yes. A square mile is exactly 2,589,988.110336 square meters, and a hectare is exactly 10,000 square meters, so a square mile works out to exactly 258.9988110336 hectares — any rounding is only in the display.
Roughly how many hectares is a square mile?
About 259 hectares. For a quick estimate you can treat a square mile as roughly 260 hectares, but for anything that matters use the exact factor above.