One square kilometre is about 247.1 acres. City areas, national parks and farms are compared this way between metric and U.S. sources.
How to use the Square Kilometers to Acres Converter
- Type the number of square kilometres into the Square kilometres field. Decimals such as 0.5 are fine.
- Read the answer in Acres. It updates as you type, with no button to press. The same amount is also shown in ha, mi², m².
- To go from acres back to square kilometres, type into the Acres field instead. Every field also has a unit menu with all 16 area units, for example m², cm², mm², ha, a, ft², in², yd², mi², cent, gaj², marla.
Results update as you type, and everything is calculated in your browser.
How it works
Both units measure area, so they are always in the same ratio: one square kilometre equals 247.10538 acres. The calculator multiplies the number of square kilometres you type by 247.10538 to give acres, and when you type into the acres field it divides by the same factor to give square kilometres. Because the ratio never changes, doubling the square kilometres always doubles the acres, for example 2 km² is 494.21076 acre.
How to convert square kilometres to acres
- Write down the value in square kilometres, for example 1 km².
- Multiply by the conversion factor 247.10538 (because 1 square kilometre = 247.10538 acre).
- 1 × 247.10538 = 247.10538 acre.
- To go back from acres to square kilometres, divide by 247.10538, or multiply by 0.0040468564.
km² to acre conversion table
| Square kilometres | Acres | Acres | Square kilometres |
|---|---|---|---|
| 0.1 km² | 24.710538 acre | 1 acre | 0.0040468564 km² |
| 0.5 km² | 123.55269 acre | 2 acre | 0.0080937128 km² |
| 1 km² | 247.10538 acre | 5 acre | 0.020234282 km² |
| 2 km² | 494.21076 acre | 10 acre | 0.040468564 km² |
| 5 km² | 1,235.5269 acre | 20 acre | 0.080937128 km² |
| 10 km² | 2,471.0538 acre | 50 acre | 0.20234282 km² |
| 100 km² | 24,710.538 acre | 100 acre | 0.40468564 km² |
| 1,000 km² | 247,105.38 acre | 1,000 acre | 4.0468564 km² |
Area units explained
- Square kilometre (km²)
- A square kilometre is a million square metres, or 100 hectares. Areas of cities, countries, lakes and national parks are reported in km².
- Acre (acre)
- An acre is exactly 43,560 square feet, about 4,047 m². Historically it was the land a team of oxen could plough in a day. It remains the land unit in the U.S. and UK.
Quick mental conversion
For a fast estimate, multiply square kilometres by about 250 to get acres; the error is about 1.2%. Use the calculator above when you need the exact figure.
Formula
1 km² = 247.10538 acres
1 acre = 0.0040468564 km²
acre = km² × 247.10538
Worked example
Inputs: Square kilometres: 1 km².
Results: Acres = 247.10538147 acre; Hectares = 100 ha; Square miles = 0.38610216 mi²; Square metres = 1,000,000 m².
Frequently asked questions
How many acres in a km²?
About 247.105 acres.
How many hectares in a km²?
100 ha.
How do I convert square kilometres to acres?
Multiply the number of square kilometres by 247.10538. For example, 1 km² × 247.10538 = 247.10538 acres.
How do I convert acres back to square kilometres?
Divide by 247.10538 (or multiply by 0.0040468564), or simply type the value into the acres field above.
What is 10 km² in acres?
10 km² = 2,471.0538 acres.
What is 100 km² in acres?
100 km² = 24,710.538 acres.
Is the square kilometres to acres conversion exact?
Yes. Both units have exact official definitions (NIST and the SI), so the factor 247.10538 is exact to every digit shown, so the only difference you may see is rounding in the last displayed digit.