Square Kilometers to Square Miles Converter (km² to mi²)

How to convert square kilometers to square miles

To convert square kilometers to square miles, multiply the number of square kilometers by 0.3861 (or divide by 2.59).

Example: 100 km² = 38.61 mi².

Useful for comparing city, park and country sizes.

Common km² to mi² conversions

1 km² = 0.3861 mi²
10 km² = 3.861 mi²
100 km² = 38.61 mi²
1,000 km² = 386.1 mi²

Square Kilometers to Square Miles conversion chart

km²	mi²
0.25 km²	0.09653 mi²
0.5 km²	0.19305 mi²
0.75 km²	0.28958 mi²
1 km²	0.3861 mi²
1.5 km²	0.57915 mi²
2 km²	0.7722 mi²
2.5 km²	0.96526 mi²
3 km²	1.158 mi²
3.5 km²	1.351 mi²
4 km²	1.544 mi²
4.5 km²	1.737 mi²
5 km²	1.931 mi²
6 km²	2.317 mi²
7 km²	2.703 mi²
8 km²	3.089 mi²
9 km²	3.475 mi²
10 km²	3.861 mi²
11 km²	4.247 mi²
12 km²	4.633 mi²
13 km²	5.019 mi²
14 km²	5.405 mi²
15 km²	5.792 mi²
16 km²	6.178 mi²
18 km²	6.95 mi²
20 km²	7.722 mi²
24 km²	9.266 mi²
25 km²	9.653 mi²
30 km²	11.583 mi²
32 km²	12.355 mi²
35 km²	13.514 mi²
40 km²	15.444 mi²
45 km²	17.375 mi²
50 km²	19.305 mi²
55 km²	21.236 mi²
60 km²	23.166 mi²
64 km²	24.711 mi²
65 km²	25.097 mi²
70 km²	27.027 mi²
75 km²	28.958 mi²
80 km²	30.888 mi²
85 km²	32.819 mi²
90 km²	34.749 mi²
100 km²	38.61 mi²
110 km²	42.471 mi²
120 km²	46.332 mi²
125 km²	48.263 mi²
128 km²	49.421 mi²
150 km²	57.915 mi²
175 km²	67.568 mi²
180 km²	69.498 mi²
200 km²	77.22 mi²
220 km²	84.942 mi²
250 km²	96.526 mi²
300 km²	115.83 mi²
400 km²	154.44 mi²
500 km²	193.05 mi²
750 km²	289.58 mi²
1,000 km²	386.1 mi²

Metric vs. U.S. customary units

The United States uses U.S. customary units — inches, feet, miles, pounds, gallons and degrees Fahrenheit — for most everyday purposes. Canada officially adopted the metric system in the 1970s, so road signs, weather forecasts, gas pumps and food labels use kilometers, degrees Celsius, liters and grams. In practice many Canadians still use feet and inches for height, pounds for body weight and square feet for homes, which is why conversions come up constantly on both sides of the border.

Exact conversion factors

Since 1959 the inch, foot, yard, mile and pound have been defined in metric terms, so these conversions are exact, not approximations:

1 inch = 2.54 cm exactly, so 1 foot = 30.48 cm and 1 mile = 1.609344 km.
1 pound = 0.45359237 kg exactly; 1 ounce = 28.349523125 g.
1 U.S. gallon = 3.785411784 liters. The imperial gallon used in the U.K. is larger: 4.54609 liters.
1 acre = 4,046.8564224 m², and 1 hectare = 10,000 m² (about 2.471 acres).

Temperature is different because the scales have different zero points: °F = °C × 9/5 + 32 and °C = (°F − 32) × 5/9. Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F) at sea level, and −40 is the same in both scales.

Quick mental shortcuts

Kilometers to miles: multiply by 0.6 (100 km ≈ 60 miles; the exact figure is 62.1).
Kilograms to pounds: double it and add 10% (70 kg → 140 + 14 = 154 lb).
Celsius to Fahrenheit: double it and add 30 for a rough estimate (20 °C → 70 °F; the exact answer is 68 °F).
Liters to U.S. gallons: divide by 4 for a quick estimate (40 L ≈ 10 gallons; exactly 10.57).

Cooking and recipe conversions

U.S. recipes measure by volume — cups, tablespoons and teaspoons — while Canadian and most international recipes use milliliters and grams. A U.S. cup is about 237 mL, but Canadian "metric" measuring cups hold 250 mL, so the difference adds up in baking. For flour, sugar and butter, weighing in grams is more accurate than cups because the density of each ingredient differs.

Popular conversions

Pick a conversion below for a dedicated page with the formula, worked examples and a complete conversion chart.

Tips for accurate conversions

Keep full precision until the final step and round only the answer — rounding intermediate numbers can add noticeable errors, especially in recipes, construction and engineering. Always check which gallon, ounce or ton a source means: U.S. and imperial units share names but not sizes, and a "fluid ounce" measures volume while an "ounce" of weight measures mass. For temperatures, remember that a temperature difference converts differently from a temperature reading: a change of 10 °C equals a change of 18 °F, without adding 32.

Popular unit conversions

Frequently asked questions

How many centimeters are in an inch?

Exactly 2.54 centimeters. To convert inches to centimeters, multiply by 2.54; to convert centimeters to inches, divide by 2.54.

How do I convert kg to pounds?

Multiply kilograms by 2.20462. For example, 70 kg × 2.20462 = 154.3 lb.

What is the formula for Celsius to Fahrenheit?

Multiply by 9/5 (1.8) and add 32. For example, 25 °C × 1.8 + 32 = 77 °F.

Is a U.S. gallon the same as a Canadian gallon?

No. Canada sells gas by the liter, but when gallons are mentioned in Canada they are sometimes imperial gallons (4.546 L), which are about 20% larger than U.S. gallons (3.785 L).

How many square feet are in a square meter?

About 10.764 square feet. A 1,000 sq ft home is roughly 92.9 m².

Sources & methodology

This calculator was last reviewed on November 2, 2026. Figures are based on the following official and primary sources:

NIST – Handbook 44, Appendix C: General Tables of Units of Measurement

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