A hectare is 10,000 square meters.
Hectares to Square miles Converter — ha to mi2
Convert Hectare (ha) to Square mile (mi2) using the exact conversion factor (1 hectare = 0.0038610216 square mile). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Hectares to Square miles converter
Converter
Agriculture Converter
Convert acres, hectares, yield, seed, fertilizer, irrigation, and application-rate units.
Context values
Some unit families need one extra value for a physically accurate result.
A square mile is 640 acres.
Result = input x 10000 / 2.58998811e+6.
Area units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Hectares to Square miles
Hectare and Square mile both measure a farming-related quantity — a land area or an application/yield rate per unit area — used to report crop yields, calculate how much fertilizer or seed a field needs, and plan irrigation. Hectare is typically associated with used worldwide, especially in agriculture, forestry, and land statistics outside the US, while Square mile is typically associated with united States (county, metro, and regional area reporting).
Formula
square miles = hectares × 0.00386102158542
This factor comes from each unit's defined relationship to the category's base unit: 1 hectare equals 10000 base units, and 1 square mile equals 2589988.11034 base units, so dividing one by the other gives the direct hectare-to-square mile factor of 0.00386102158542.
Simple example
1 ha × 0.003861021585 = 0.0038610216 mi2
1 hectare = 0.0038610216 square miles.
Real-world example
100 ha × 0.003861021585 = 0.3861021585 mi2
100 hectares = 0.3861021585 square miles.
Conversion table
| Hectare (ha) | Square mile (mi2) |
|---|---|
| 1 ha | 0.0038610216 mi2 |
| 5 ha | 0.0193051079 mi2 |
| 10 ha | 0.0386102159 mi2 |
| 50 ha | 0.1930510793 mi2 |
| 100 ha | 0.3861021585 mi2 |
| 500 ha | 1.930510793 mi2 |
Reverse conversion: Square mile to Hectare
0.0038610216 mi2 × 258.998811 = 1.000000004 ha
0.0038610216 square miles = 1.000000004 hectares.
hectares = square miles × 258.998811034
For a page dedicated to this direction, see Square mile to Hectare.
Hectare vs. Square mile
| Aspect | Hectare | Square mile |
|---|---|---|
| Family | non-SI metric unit accepted for use with SI | US/imperial customary unit |
| Typical use | Reporting farmland and crop area in international agricultural statistics | US city, county, and regional area statistics |
| Where it's used | Used worldwide, especially in agriculture, forestry, and land statistics outside the US | United States (county, metro, and regional area reporting) |
Understanding the Hectare
Hectare (ha) measures area. A hectare is exactly 10,000 square meters — the area of a 100 m × 100 m square. It is classified as a non-SI metric unit accepted for use with SI.
Where it's used: Used worldwide, especially in agriculture, forestry, and land statistics outside the US
Uses of the Hectare today
- Reporting farmland and crop area in international agricultural statistics
- Forestry and land-use planning
- Real estate and cadastral survey in metric countries
History of the Hectare
The hectare derives from the 'are,' a metric area unit (100 m²) introduced during the French Revolutionary metric reforms of the 1790s. 'Hecto-' is simply the SI prefix for 100, so a hectare is 100 ares.
Although not itself an SI unit, the hectare is officially accepted for use alongside SI units by the BIPM because of its practical importance in land measurement, and it remains the standard land-area unit in most of the world.
Historical origin. Hectare was not the invention of a single named person; it developed through the process described above.
Understanding the Square mile
Square mile (mi2) measures area. A square mile is exactly 2,589,988.110336 square meters, derived from the international mile fixed in 1959. It is classified as a US/imperial customary unit.
Where it's used: United States (county, metro, and regional area reporting)
Uses of the Square mile today
- US city, county, and regional area statistics
- Population density reporting (people per square mile)
- Land-use and geography in US contexts
History of the Square mile
The square mile follows directly from the statute mile, itself fixed at exactly 1,609.344 meters by the 1959 International Yard and Pound Agreement; squaring that value gives the modern square mile.
Historical origin. Square mile was not the invention of a single named person; it developed through the process described above.
Hectare — sources
- BIPM SI Brochure, 9th edition — Non-SI units accepted for use with SI — Lists the hectare as an accepted non-SI unit.
Square mile — sources
- NIST — International yard and pound (1959) — Basis for the modern mile and its derived area unit.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many square miles are in 1 hectare?
1 hectare equals 0.0038610216 square miles, using the exact defined conversion factor rather than an estimate.
How do I convert hectare to square mile?
Multiply the hectare value by 0.003861021585. The converter above does this instantly to whatever precision you set.
How do I convert square mile back to hectare?
Use the reverse factor: 1 square mile equals 258.998811 hectares. You can also use the swap control in the converter above to flip the direction instantly.
What is a hectare?
Hectare (ha) measures area. A hectare is exactly 10,000 square meters — the area of a 100 m × 100 m square. It is classified as a non-SI metric unit accepted for use with SI.
What is a square mile?
Square mile (mi2) measures area. A square mile is exactly 2,589,988.110336 square meters, derived from the international mile fixed in 1959. It is classified as a US/imperial customary unit.
Is the hectare to square mile conversion exact?
Yes. A square mile is exactly 2,589,988.110336 square meters, derived from the international mile fixed in 1959. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the hectare still used today?
Used worldwide, especially in agriculture, forestry, and land statistics outside the US
What's the difference between a yield rate and an application rate?
A yield rate describes how much of a crop is harvested per unit of land area (for example, tonnes per hectare). An application rate describes how much of an input like fertilizer or seed is applied per unit of land area. Both are commonly expressed using the same kind of mass-per-area units.