Square miles to Square kilometers Converter
1 square mile (mi²) equals 2.58998811034 square kilometers (km²).
Quick answer
To convert square miles to km², multiply by 2.59. 1 sq mi ≈ 2.59 km².
- 1 square mile = 2.58998811 square kilometers
- 1 square kilometer = 0.3861021585 square miles
- Formula: km² = mi² × 2.58998811034
- Quick estimate: multiply by 2.6: 100 sq mi ≈ 260 km² (exact 259).
1 square mile = 2.58998811 square kilometers
How to convert square miles to square kilometers
km² = mi² × 2.58998811034
To convert square miles to square kilometers, multiply the number of square miles by 2.58998811034.
Example: 42 mi² to km²
- Start with the value in square miles: 42 mi².
- Multiply by 2.58998811034: 42 × 2.58998811034 = 108.7795006.
- Result: 42 square miles = 108.7795006 square kilometers.
Going the other way, 1 square kilometer = 0.386102158542 square miles, so to convert square kilometers back to square miles you divide by the same number. See square kilometers to square miles.
Where the conversion factor comes from
A square mile is 5,280 × 5,280 = 27,878,400 square feet, which is exactly 2.589988110336 km² (640 acres). One square kilometer is 0.3861 square miles or 100 hectares.
Mental math: mi² to km² in your head
Multiply by 2.6 and take off a little.
When you need to convert square miles to square kilometers
- US state, county and city areas.
- Comparing land areas internationally.
Common mistakes
- Using 1.609 (the length factor).
Everyday square miles in square kilometers
| Example | Square miles | Square kilometers |
|---|---|---|
| Central Park | 1.317 mi² | 3.411 km² |
| Washington, DC | 68.3 mi² | 176.9 km² |
| Rhode Island | 1,545 mi² | 4,001.5 km² |
| Texas | 268,596 mi² | 695,660 km² |
Square miles to square kilometers conversion table
| Square miles (mi²) | Square kilometers (km²) |
|---|---|
| 0.1 mi² | 0.258998811 km² |
| 0.2 mi² | 0.5179976221 km² |
| 0.3 mi² | 0.7769964331 km² |
| 0.4 mi² | 1.035995244 km² |
| 0.5 mi² | 1.294994055 km² |
| 0.6 mi² | 1.553992866 km² |
| 0.7 mi² | 1.812991677 km² |
| 0.8 mi² | 2.071990488 km² |
| 0.9 mi² | 2.330989299 km² |
| 1 mi² | 2.58998811 km² |
| 1.5 mi² | 3.884982166 km² |
| 2 mi² | 5.179976221 km² |
| 2.5 mi² | 6.474970276 km² |
| 3 mi² | 7.769964331 km² |
| 3.5 mi² | 9.064958386 km² |
| 4 mi² | 10.35995244 km² |
| 4.5 mi² | 11.6549465 km² |
| 5 mi² | 12.94994055 km² |
| 6 mi² | 15.53992866 km² |
| 7 mi² | 18.12991677 km² |
| 7.5 mi² | 19.42491083 km² |
| 8 mi² | 20.71990488 km² |
| 9 mi² | 23.30989299 km² |
| 10 mi² | 25.8998811 km² |
| 11 mi² | 28.48986921 km² |
| 12 mi² | 31.07985732 km² |
| 13 mi² | 33.66984543 km² |
| 14 mi² | 36.25983354 km² |
| 15 mi² | 38.84982166 km² |
| 16 mi² | 41.43980977 km² |
| 17 mi² | 44.02979788 km² |
| 18 mi² | 46.61978599 km² |
| 19 mi² | 49.2097741 km² |
| 20 mi² | 51.79976221 km² |
| 21 mi² | 54.38975032 km² |
| 22 mi² | 56.97973843 km² |
| 23 mi² | 59.56972654 km² |
| 24 mi² | 62.15971465 km² |
| 25 mi² | 64.74970276 km² |
| 26 mi² | 67.33969087 km² |
More mi² to km² values
- 27 mi²
- 28 mi²
- 29 mi²
- 30 mi²
- 31 mi²
- 32 mi²
- 33 mi²
- 34 mi²
- 35 mi²
- 36 mi²
- 37 mi²
- 38 mi²
- 39 mi²
- 40 mi²
- 41 mi²
- 42 mi²
- 43 mi²
- 44 mi²
- 45 mi²
- 46 mi²
- 47 mi²
- 48 mi²
- 49 mi²
- 50 mi²
- 51 mi²
- 52 mi²
- 53 mi²
- 54 mi²
- 55 mi²
- 56 mi²
- 57 mi²
- 58 mi²
- 59 mi²
- 60 mi²
- 61 mi²
- 62 mi²
- 63 mi²
- 64 mi²
- 65 mi²
- 66 mi²
- 67 mi²
- 68 mi²
- 69 mi²
- 70 mi²
- 71 mi²
- 72 mi²
- 73 mi²
- 74 mi²
- 75 mi²
- 76 mi²
- 77 mi²
- 78 mi²
- 79 mi²
- 80 mi²
- 81 mi²
- 82 mi²
- 83 mi²
- 84 mi²
- 85 mi²
- 86 mi²
- 87 mi²
- 88 mi²
- 89 mi²
- 90 mi²
- 91 mi²
- 92 mi²
- 93 mi²
- 94 mi²
- 95 mi²
- 96 mi²
- 97 mi²
- 98 mi²
- 99 mi²
- 100 mi²
- 110 mi²
- 120 mi²
- 130 mi²
- 140 mi²
- 150 mi²
- 160 mi²
- 170 mi²
- 180 mi²
- 190 mi²
- 200 mi²
- 210 mi²
- 220 mi²
- 230 mi²
- 240 mi²
- 250 mi²
- 260 mi²
- 270 mi²
- 280 mi²
- 290 mi²
- 300 mi²
- 310 mi²
- 320 mi²
- 330 mi²
- 340 mi²
- 350 mi²
- 360 mi²
- 370 mi²
- 380 mi²
- 390 mi²
- 400 mi²
- 410 mi²
- 420 mi²
- 430 mi²
- 440 mi²
- 450 mi²
- 460 mi²
- 470 mi²
- 480 mi²
- 490 mi²
- 500 mi²
- 600 mi²
- 700 mi²
- 800 mi²
- 900 mi²
- 1,000 mi²
- 1,200 mi²
- 1,500 mi²
- 2,000 mi²
- 2,500 mi²
- 3,000 mi²
- 4,000 mi²
- 5,000 mi²
- 10,000 mi²
What is a square mile?
The square mile is the area of a square one mile on each side, 640 acres or about 2.59 square kilometers.
What is a square kilometer?
The square kilometer is the area of a square one kilometer on each side, one million square meters or 100 hectares, about 0.386 square miles.
Convert square miles to other units
- Square miles to square meters
- Square miles to square feet
- Square miles to acres
- Square miles to hectares
- Square miles to square centimeters
- Square miles to square yards
- Square miles to square inches
- Square miles to square millimeters
- Square miles to pyeong
- Square miles to bighas
- All square mile conversions →
Convert other units to square kilometers
- Square meters to square kilometers
- Square feet to square kilometers
- Acres to square kilometers
- Hectares to square kilometers
- Square centimeters to square kilometers
- Square yards to square kilometers
- Square inches to square kilometers
- Square millimeters to square kilometers
- Pyeong to square kilometers
- Bighas to square kilometers
- All square kilometer conversions →
Frequently asked questions
How many square kilometers are in a square mile?
One square mile is 2.58998811 square kilometers.
How many square miles are in a square kilometer?
One square kilometer is 0.3861021585 square miles.
What is the formula to convert square miles to square kilometers?
km² = mi² × 2.58998811034.
How many km² is a square mile?
2.59 km².