How many hectares are in 1 square mile?

1 square mile equals 258.999 ha.

How do I convert hectares back to square miles?

Use the reverse converter: 1 hectare equals 0.00386102 mi².

Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.

To convert square miles to hectares, multiply the value by 258.998811.

ha = mi² × 258.998811

40 mi² × 258.998811 = 10359.95 ha

Square Mile (mi²): Used for large land areas in the US and UK. Equal to 640 acres.
Hectare (ha): Used for farmland and forests worldwide. Equal to 10,000 square metres, introduced in the French metric system in 1795.

How do I convert square miles to hectares?: To convert square miles to hectares, multiply the value by 258.998811.
How many hectares are in 1 square mile?: 1 square mile equals 258.999 ha.
How many hectares are in 10 square miles?: 10 mi² equals 2589.99 ha.
How do I convert hectares back to square miles?: Use the reverse converter: 1 hectare equals 0.00386102 mi².
Is this converter accurate?: Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.