Convert Square miles to Square kilometres
1 square mile is 2.59 km². One square mile is exactly 2.58998811034 square kilometres.
One square mile is 2.5899881 square kilometres. To convert square miles to square kilometres, multiply by 2.5899881; to go the other way, divide by 2.5899881 or multiply by 0.38610216. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Office of Weights and Measures. Exactly 640 acres — one section of the US Public Land Survey, the grid the Midwest is drawn on.
Factor checked against the defining standard · How we check
- Square miles × 2.5899881
1 * 2.58998812.59 km²
1 square mile in every area unit
| Unit | Value | Exact factor |
|---|---|---|
| square inches | 4,014,489,600 sq in | × 4,014,489,600 |
| square feet | 27,878,400 sq ft | × 27,878,400 |
| square yards | 3,097,600 sq yd | × 3,097,600 |
| acres | 640 ac | × 640 |
| square meters | 2,589,988.11 m² | × 2,589,988.11034 |
| square millimetres | 2,589,988,110,000 mm² | × 2,589,988,110,340 |
| square centimetres | 25,899,881,100 cm² | × 25,899,881,103.4 |
| square kilometres | 2.58998811 km² | × 2.58998811034 |
| square miles (as entered) | 1 mi² | — |
| hectares | 258.998811 ha | × 258.998811034 |
Factors are entered by hand from NIST Office of Weights and Measures rather than derived from a units library, so the ones that terminate are exact rather than rounded.
The same converter answers this pair however it is written: sqmi to sqkm is how the symbols are typed on a keyboard with no superscript on it.
How do you convert square miles to square kilometres? The converter and the working
- 1.Take the measurement in square miles.
- 2.Multiply by 2.5899881 — that is how many square kilometres fit in one square mile.
- 3.To go back the other way, divide by 2.5899881, or multiply by 0.38610216.
Worked example: 25 square miles to square kilometres
- Formula
- mi² × 2.5899881 = km²
- Arithmetic
- 25 × 2.5899881 = 64.75 km²
- Answer
- 25 mi² = 64.75 km²
The factor is rounded for display; the figure above is computed from the full value.
Square miles to square kilometres conversion table
| Square miles | Square kilometres |
|---|---|
| 1 mi² | 2.59 km² |
| 2 mi² | 5.18 km² |
| 3 mi² | 7.77 km² |
| 4 mi² | 10.36 km² |
| 5 mi² | 12.95 km² |
| 6 mi² | 15.54 km² |
| 7 mi² | 18.13 km² |
| 8 mi² | 20.72 km² |
| 9 mi² | 23.31 km² |
| 10 mi² | 25.9 km² |
| 12 mi² | 31.08 km² |
| 15 mi² | 38.85 km² |
| 20 mi² | 51.8 km² |
| 25 mi² | 64.75 km² |
| 50 mi² | 129.5 km² |
| 100 mi² | 259 km² |
| 200 mi² | 518 km² |
| 300 mi² | 777 km² |
| 500 mi² | 1,294.99 km² |
| 1000 mi² | 2,589.99 km² |
| 2000 mi² | 5,179.98 km² |
| 5000 mi² | 12,949.94 km² |
| 10000 mi² | 25,899.88 km² |
What is a square mile?
Exactly 640 acres — one section of the US Public Land Survey, the grid the Midwest is drawn on. 2.59 square kilometres, and the reason a rural address is often "section 12".
What is a square kilometre?
A million square metres, or 100 hectares. The unit land area and population density are published in everywhere except the US.
How many square kilometres are in a square mile?
One square mile is 2.5899881 square kilometres. Going the other way, one square kilometre is 0.38610216 square miles. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every area unit here
The whole group — 10 units with their symbols and the size of each one in square meters — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a square mile.
Cite this page
- APA
- Rule Calculator. (2026). Convert Square miles to square kilometres. Rule Calculator. https://rulecalculators.com/convert/square-mile-to-square-kilometer
- MLA
- "Convert Square miles to square kilometres." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/square-mile-to-square-kilometer.
- Chicago
- Rule Calculator. "Convert Square miles to square kilometres." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/square-mile-to-square-kilometer.
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Questions people actually ask
- How many square kilometres are in a square mile?
- 2.5899881. A million square metres, or 100 hectares. The unit land area and population density are published in everywhere except the US.
- How do I convert square kilometres back to square miles?
- Divide by 2.5899881, or multiply by 0.38610216 — they are the same operation.
Other area conversions
Square kilometres to square miles — the same conversion the other way.