Square Miles to Square Kilometres Converter
1 square mile = 2.58999 square kilometres.
Enter a value
Result
1 square mile =
2.58999 km²
1 mi² × 2.58999 = 2.58999 km²
1 ft² = 0.09290304 m² exactly
The working
- 1. Convert 1 mi² to square metres: 1 × 2,589,990 = 2,589,990.
- 2. Convert to km²: 2,589,990 ÷ 1,000,000 = 2.58999.
1 mi² in every unit
Sizes for scale
- Studio flat
- 37 m² (400 ft²)
- Tennis court
- 261 m²
- Football pitch
- 7,140 m²
- One acre
- 4,047 m²
Conversion table
Square miles to Square kilometres
| Square miles | Square kilometres |
|---|---|
| 1 | 2.59 |
| 2 | 5.18 |
| 3 | 7.77 |
| 4 | 10.36 |
| 5 | 12.95 |
| 6 | 15.54 |
| 7 | 18.13 |
| 8 | 20.72 |
| 9 | 23.31 |
| 10 | 25.9 |
| 15 | 38.85 |
| 20 | 51.8 |
| 25 | 64.75 |
| 50 | 129.5 |
| 100 | 259 |
Square kilometres to Square miles
| Square kilometres | Square miles |
|---|---|
| 1 | 0.3861 |
| 2 | 0.7722 |
| 3 | 1.1583 |
| 4 | 1.5444 |
| 5 | 1.9305 |
| 6 | 2.3166 |
| 7 | 2.7027 |
| 8 | 3.0888 |
| 9 | 3.4749 |
| 10 | 3.861 |
| 15 | 5.7915 |
| 20 | 7.722 |
| 25 | 9.6526 |
| 50 | 19.305 |
| 100 | 38.61 |
Formula and worked example
square kilometres = square miles × 2.58998811.
Convert 100 square miles to square kilometres: 100 × 2.5899881 = 258.999 km².
When you need this
Converting US and UK land areas, such as counties and parks, into square kilometres.
Questions people ask
How many square kilometres are in a square mile?
One square mile is 2.5899881 square kilometres.
How do I convert square miles to square kilometres?
Multiply the number of square miles by 2.5899881.
What is 10 mi² in km²?
10 square miles is 25.8999 square kilometres.
How do I convert square kilometres back to square miles?
Multiply by 0.38610216: one square kilometre is 0.38610216 square miles.
Related conversions
How we calculate this
We use the standard published formula or definition for this calculation, and we show the working so you can check it. Source: NIST Special Publication 811, Guide for the Use of the International System of Units.
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