Hectares to Square Miles
An instant hectares-to-square miles converter, with the formula and a reference table below.
| Hectares | Square Miles |
|---|---|
| 1 ha | 0.003861 mi² |
| 2 ha | 0.007722 mi² |
| 3 ha | 0.011583 mi² |
| 5 ha | 0.019305 mi² |
| 10 ha | 0.03861 mi² |
| 25 ha | 0.096526 mi² |
| 50 ha | 0.193051 mi² |
| 100 ha | 0.386102 mi² |
How to use
- Enter a value in the Hectares field.
- The Square Miles figure appears immediately — no button to press.
- Typing in the Square Miles field converts back to Hectares the same way.
- Use the reference table for the values that come up most often.
Hectares to Square Miles formula
The factor from hectares to square miles is 0.00386102159.
mi² = ha × 0.00386102159
Why this factor: the hectare and the square mile are both defined against the square meter, so dividing one definition by the other gives 0.00386102159 directly. Both definitions are set out in full below.
To go the other way, divide by 0.00386102159 — or use the Square Miles to Hectares converter, which is the same calculation reversed.
Worked example
Start with 1000 ha. Multiply by 0.00386102159 to get 3.861022 mi².
1000 ha × 0.00386102159 = 3.861022 mi²
The converter above does this for any value you type, in either direction.
What is a hectare?
A hectare is the standard metric unit of land area — a 100-meter square.
Definition: Exactly 10,000 square meters, which is one square hectometer.
Where it is used: Agricultural and forestry land, development sites, and land-use statistics worldwide.
Worth knowing: Roughly two and a half acres, and almost exactly the area of an international rugby pitch.
What is a square mile?
A square mile is the area of a one-mile square, used for large land areas in the US and UK.
Definition: Exactly 2,589,988.110336 square meters, and exactly 640 acres.
Where it is used: County, state and metropolitan areas, and population density in the US.
Hectares vs Square Miles
The hectare is a metric unit while the square mile is an imperial unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many square miles are in a hectare?
One hectare equals 0.00386102159 square miles.
What is the formula to convert hectares to square miles?
Multiply the number of hectares by 0.00386102159. To reverse it, divide by 0.00386102159 instead.
How do I convert square miles back to hectares?
Divide by 0.00386102159, which is the same as multiplying by 258.998811.
How many square miles are in 10 hectares?
10 ha works out to 0.03861 mi².
Is there anything to watch out for with hectares?
Roughly two and a half acres, and almost exactly the area of an international rugby pitch.
How is the hectare defined?
Exactly 10,000 square meters, which is one square hectometer.