Square metric area unit.
Square Hectometers to Acres Converter — hm2 to ac
Convert Square Hectometer (hm2) to Acre (ac) using the exact conversion factor (1 square hectometer = 2.471053815 acre). See the formula, worked examples, conversion table, history, and common uses.
Square Hectometers to Acres converter
Converter
Area Converter
Convert land, construction, mapping, survey, and scientific area units.
Context values
Some unit families need one extra value for a physically accurate result.
An international acre is 4,046.8564224 square meters.
Result = input x 10000 / 4046.856422.
Area uses the square meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Square Hectometers to Acres
Comparing Square Hectometer and Acre is common in agriculture and real estate, where US land is typically measured in acres and most of the rest of the world uses hectares. Specifically: Square metric area unit, and an international acre is 4,046.8564224 square meters.
Formula
acres = square hectometers × 2.47105381467
This factor comes from each unit's defined relationship to the category's base unit: 1 square hectometer equals 10000 base units, and 1 acre equals 4046.8564224 base units, so dividing one by the other gives the direct square hectometer-to-acre factor of 2.47105381467.
Simple example
1 hm2 × 2.471053815 = 2.471053815 ac
1 square hectometer = 2.471053815 acres.
Real-world example
10 hm2 × 2.471053815 = 24.71053815 ac
10 square hectometers = 24.71053815 acres.
Conversion table
| Square Hectometer (hm2) | Acre (ac) |
|---|---|
| 1 hm2 | 2.471053815 ac |
| 5 hm2 | 12.35526907 ac |
| 10 hm2 | 24.71053815 ac |
| 25 hm2 | 61.77634537 ac |
| 50 hm2 | 123.5526907 ac |
| 100 hm2 | 247.1053815 ac |
Reverse conversion: Acre to Square Hectometer
2.471053815 ac × 0.4046856422 = 1 hm2
2.471053815 acres = 1 square hectometers.
square hectometers = acres × 0.40468564224
For a page dedicated to this direction, see Acre to Square Hectometer.
Understanding the Square Hectometer (hm2)
Square metric area unit.
Understanding the Acre
Acre (ac) measures area. The international acre is defined as exactly 4,046.8564224 square meters. It is classified as a US/imperial customary unit.
Where it's used: United States United Kingdom (informal/historical, land registry legacy) Countries with historical British land-survey systems
International acre vs. US survey acre. The US survey acre, based on the US survey foot, differs from the international acre by about two parts per million. The US retired the survey foot/acre for federal use at the end of 2022.
Uses of the Acre today
- Measuring farmland, ranch, and rural property size in the US
- Real estate listings and zoning for land parcels
- Forestry and land-management reporting
History of the Acre
The acre originated in medieval England as a practical field measurement: the area a yoke of oxen could plow in one day, roughly a furlong (660 ft) long by a chain (66 ft) wide, giving the 43,560 square feet still used today.
Edward I's 1305 statute formalized this figure. In 1959, the same International Yard and Pound Agreement that fixed the pound also fixed the international acre at exactly 4,046.8564224 m², though the US separately retained a slightly different 'US survey acre' for some legacy land records until it was phased out in 2023.
Historical origin. Acre was not the invention of a single named person; it developed through the process described above.
Acre — sources
- NIST — US Survey Foot: Revised Unit Conversion Factors — Documents the 1959 international acre definition and the 2022/2023 survey-foot retirement.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many acres are in 1 square hectometer?
1 square hectometer equals 2.471053815 acres, using the exact defined conversion factor rather than an estimate.
How do I convert square hectometer to acre?
Multiply the square hectometer value by 2.471053815. The converter above does this instantly to whatever precision you set.
How do I convert acre back to square hectometer?
Use the reverse factor: 1 acre equals 0.4046856422 square hectometers. You can also use the swap control in the converter above to flip the direction instantly.
What is a square hectometer?
Square Hectometer (hm2) is a unit of area.
What is a acre?
Acre (ac) measures area. The international acre is defined as exactly 4,046.8564224 square meters. It is classified as a US/imperial customary unit.
Is the square hectometer to acre conversion exact?
Yes. The international acre is defined as exactly 4,046.8564224 square meters. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between international acre vs. us survey acre?
The US survey acre, based on the US survey foot, differs from the international acre by about two parts per million. The US retired the survey foot/acre for federal use at the end of 2022.