One square mile is exactly 258.9988110336 hectares, about 259 ha. Multiply square miles by 259 to get hectares. People use this direction to express a US section, ranch or watershed in the unit that farmers, foresters and land agencies use almost everywhere else. Canadian farmland, for instance, was surveyed in square-mile sections much like the US system, but farm statistics in Canada are now often given in hectares, so converting a section to hectares is a common step when comparing old and new records.
Formula
Square Miles to Hectares conversion table
| Square Miles | Hectares |
|---|---|
| 0.25 mi² | 64.7497 ha |
| 0.5 mi² | 129.4994 ha |
| 1 mi² | 258.9988 ha |
| 2 mi² | 517.9976 ha |
| 3 mi² | 776.9964 ha |
| 4 mi² | 1,036 ha |
| 5 mi² | 1,294.99 ha |
| 6 mi² | 1,553.99 ha |
| 7 mi² | 1,812.99 ha |
| 8 mi² | 2,071.99 ha |
| 9 mi² | 2,330.99 ha |
| 10 mi² | 2,589.99 ha |
| 15 mi² | 3,884.98 ha |
| 20 mi² | 5,179.98 ha |
| 25 mi² | 6,474.97 ha |
| 30 mi² | 7,769.96 ha |
| 40 mi² | 10,359.95 ha |
| 50 mi² | 12,949.94 ha |
| 60 mi² | 15,539.93 ha |
| 70 mi² | 18,129.92 ha |
| 75 mi² | 19,424.91 ha |
| 80 mi² | 20,719.9 ha |
| 90 mi² | 23,309.89 ha |
| 100 mi² | 25,899.88 ha |
| 250 mi² | 64,749.7 ha |
| 500 mi² | 129,499.41 ha |
| 1,000 mi² | 258,998.81 ha |
Where you’ll use it
A US section of land, one square mile or 640 acres, is about 259 hectares, and a quarter section is about 64.75 hectares. Agricultural researchers, foreign buyers of US farmland and international agencies comparing land use all convert in this direction. 100 square miles is about 25,900 hectares, which also equals about 259 km², since 100 hectares make a square kilometer.
Tip: 259 is close enough for almost every purpose; the error is about five parts per million. Just remember that the section itself may not be exactly 640 acres on the ground.