Square Mile (mi²)
A square mile is the area of a square one mile per side, equal to 640 acres or about 2.59 square kilometers.
Square miles describe city limits, national parks, and geographic regions in the US and UK.
Square Mile to Square Kilometer
Convert square mile to square kilometer instantly. Type in either field — results update live.
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Area Square Mile Square Kilometer
1 square mile = 2.5899881103 square kilometers
Unit
Unit
Conversion table
Selected mi² values converted to km² using the exact factor from this tool.
| mi² | km² |
|---|---|
| 0.01 | 0.0258998811 |
| 0.1 | 0.258998811 |
| 1 | 2.5899881103 |
| 2 | 5.1799762207 |
| 3 | 7.769964331 |
| 5 | 12.9499405517 |
| 10 | 25.8998811034 |
| 20 | 51.7997622067 |
| 50 | 129.4994055168 |
| 100 | 258.9988110336 |
| 1,000 | 2,589.988110336 |
How to convert
Exact conversion factors in both directions, plus a worked example.
1 mi² = 2.5899881103 km²
1 km² = 0.3861021585 mi²
To convert square mile to square kilometer, multiply by 2.5899881103.
To convert square kilometer to square mile, multiply by 0.3861021585.
Example: convert 10 mi² to km²
10 × 2.5899881103 = 25.8998811034 km²
About these units
Short background on the units used in this conversion.
Square Kilometer (km²)
A square kilometer is one million square meters — a convenient scale for towns, lakes, and protected areas.
Square kilometers appear on maps, census data, and environmental reports worldwide.
Frequently asked questions
How many square kilometers are in one square mile?
One square mile equals 2.5899881103 square kilometers. Multiply your square miles value by 2.5899881103 to convert to square kilometers.
What is the conversion formula?
km² = mi² × 2.5899881103The reverse is
mi² = km² × 0.3861021585, using the same exact factors as this converter.Is this Square Mile to Square Kilometer converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.
All square mile conversions
Jump to any area conversion starting from square mile — including the reverse direction and every other unit in our dataset.
square kilometer (km²) → square mile (mi²)
square mile (mi²) → square meter (m²)square mile (mi²) → square centimeter (cm²)square mile (mi²) → square millimeter (mm²)square mile (mi²) → square micrometer (µm²)square mile (mi²) → square nanometer (nm²)square mile (mi²) → square decimeter (dm²)square mile (mi²) → square dekameter (dam²)square mile (mi²) → square hectometer (hm²)square mile (mi²) → hectare (ha)square mile (mi²) → are (a)square mile (mi²) → barn (b)square mile (mi²) → square mile (us survey) (mi² surv)square mile (mi²) → sectionsquare mile (mi²) → square yard (yd²)square mile (mi²) → square foot (ft²)square mile (mi²) → square foot (us survey) (ft² surv)square mile (mi²) → sabinsquare mile (mi²) → square inch (in²)square mile (mi²) → circular inch (circ in)square mile (mi²) → acre (ac)square mile (mi²) → acre (us survey) (ac surv)square mile (mi²) → square rod (rd²)square mile (mi²) → square rod (us survey) (rd² surv)square mile (mi²) → square perch (perch²)square mile (mi²) → square pole (pole²)square mile (mi²) → square chain (ch²)square mile (mi²) → roodsquare mile (mi²) → township (twp)square mile (mi²) → homesteadsquare mile (mi²) → square mil (mil²)square mile (mi²) → circular mil (circ mil)square mile (mi²) → square nautical mile (NM²)square mile (mi²) → arpentsquare mile (mi²) → cuerdasquare mile (mi²) → plazasquare mile (mi²) → varas castellanas cuad (varas cast.)square mile (mi²) → varas conuqueras cuad (varas con.)square mile (mi²) → electron cross section (σₑ)