Area converter
Square Miles to Square Kilometers
Square Miles and Square Kilometers measure the same quantity in different unit systems. The relationship is 1 mi² = 2.589988 km², which gives 2.589988 km² per mi². Below you can convert any value, check a worked example and read the full chart.
Formula 1 mi² = 2.589988 km²
Need the other direction? Square Kilometers to Square Miles.
How to convert Square Miles to Square Kilometers
A square mile is 2,589,988.11 square metres, or 640 acres. A square kilometre is one million square metres, used for land and administrative areas.
To convert Square Miles to Square Kilometers, multiply the value in mi² by 2.589988. For example, 10 mi² × 2.589988 = 25.899881 km². This works because the ratio between the two units is constant for every value in area.
Worked examples
| mi² | km² |
|---|---|
| 1 mi² | 2.589988 km² |
| 2.5 mi² | 6.47497 km² |
| 5 mi² | 12.949941 km² |
| 10 mi² | 25.899881 km² |
| 25 mi² | 64.749703 km² |
| 50 mi² | 129.499406 km² |
| 100 mi² | 258.998811 km² |
Reverse conversion
| km² | mi² |
|---|---|
| 1 km² | 0.38610216 mi² |
| 5 km² | 1.930511 mi² |
| 10 km² | 3.861022 mi² |
| 25 km² | 9.652554 mi² |
| 50 km² | 19.305108 mi² |
| 100 km² | 38.610216 mi² |
When this conversion is useful
This is the calculation you need when you are comparing property listings, land size or building materials across measurement systems. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 mi² is 2,589.99 km².
Is the conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
mi² to km² conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Square Miles (mi²) | Square Kilometers (km²) |
|---|---|
| 1 mi² | 2.589988 km² |
| 2 mi² | 5.179976 km² |
| 3 mi² | 7.769964 km² |
| 4 mi² | 10.359952 km² |
| 5 mi² | 12.949941 km² |
| 6 mi² | 15.539929 km² |
| 7 mi² | 18.129917 km² |
| 8 mi² | 20.719905 km² |
| 9 mi² | 23.309893 km² |
| 10 mi² | 25.899881 km² |
| 11 mi² | 28.489869 km² |
| 12 mi² | 31.079857 km² |
| 13 mi² | 33.669845 km² |
| 14 mi² | 36.259834 km² |
| 15 mi² | 38.849822 km² |
| 16 mi² | 41.43981 km² |
| 17 mi² | 44.029798 km² |
| 18 mi² | 46.619786 km² |
| 19 mi² | 49.209774 km² |
| 20 mi² | 51.799762 km² |
| 21 mi² | 54.38975 km² |
| 22 mi² | 56.979738 km² |
| 23 mi² | 59.569727 km² |
| 24 mi² | 62.159715 km² |
| 25 mi² | 64.749703 km² |
| 26 mi² | 67.339691 km² |
| 27 mi² | 69.929679 km² |
| 28 mi² | 72.519667 km² |
| 29 mi² | 75.109655 km² |
| 30 mi² | 77.699643 km² |
| 31 mi² | 80.289631 km² |
| 32 mi² | 82.87962 km² |
| 33 mi² | 85.469608 km² |
| 34 mi² | 88.059596 km² |
| 35 mi² | 90.649584 km² |
| 36 mi² | 93.239572 km² |
| 37 mi² | 95.82956 km² |
| 38 mi² | 98.419548 km² |
| 39 mi² | 101.009536 km² |
| 40 mi² | 103.599524 km² |
| 41 mi² | 106.189513 km² |
| 42 mi² | 108.779501 km² |
| 43 mi² | 111.369489 km² |
| 44 mi² | 113.959477 km² |
| 45 mi² | 116.549465 km² |
| 46 mi² | 119.139453 km² |
| 47 mi² | 121.729441 km² |
| 48 mi² | 124.319429 km² |
| 49 mi² | 126.909417 km² |
| 50 mi² | 129.499406 km² |
| 60 mi² | 155.399287 km² |
| 70 mi² | 181.299168 km² |
| 80 mi² | 207.199049 km² |
| 90 mi² | 233.09893 km² |
| 100 mi² | 258.998811 km² |
Frequently asked questions
How many Square Kilometers are in 1 Square Miles?
1 mi² equals 2.589988 km².
How do I convert Square Miles to Square Kilometers?
Multiply the mi² value by 2.589988. Example: 25 mi² = 64.749703 km².
What is 2.5 mi² in km²?
2.5 mi² = 6.47497 km².
Is the mi² to km² conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.