Convert length, weight, temperature and volume instantly — no signup, no fuss.
The world uses two main measurement systems: the metric system (SI), adopted by most countries, and the Imperial/US Customary system, still prevalent in the United States, Liberia, and Myanmar. When you travel, cook an international recipe, shop online from another country, or read a scientific paper, you constantly need to switch between these systems.
Errors in unit conversion have caused real-world disasters. In 1999, NASA lost the Mars Climate Orbiter — a $327 million spacecraft — because one engineering team used metric newtons while another used Imperial pound-force. The mismatch sent the probe too close to Mars, where it was destroyed. Getting unit conversion right is not just convenient; in professional and scientific contexts it can be critical.
Our converter covers the four most-needed everyday categories: length (kilometers, miles, feet, inches, meters, centimeters, yards), weight/mass (kilograms, pounds, ounces, grams, stones), temperature (Celsius, Fahrenheit, Kelvin), and volume (liters, US gallons, UK gallons, US cups, milliliters, fluid ounces, pints, quarts).
| From | To km | To miles | To feet | To inches | To meters |
|---|---|---|---|---|---|
| 1 kilometer (km) | 1 | 0.6214 | 3,280.84 | 39,370 | 1,000 |
| 1 mile | 1.6093 | 1 | 5,280 | 63,360 | 1,609.3 |
| 1 meter (m) | 0.001 | 0.000621 | 3.2808 | 39.370 | 1 |
| 1 foot (ft) | 0.000305 | 0.000189 | 1 | 12 | 0.3048 |
| 1 inch (in) | 0.0000254 | 0.0000158 | 0.0833 | 1 | 0.0254 |
| 1 yard (yd) | 0.000914 | 0.000568 | 3 | 36 | 0.9144 |
| From | To kg | To lbs | To oz | To grams | To stones |
|---|---|---|---|---|---|
| 1 kilogram (kg) | 1 | 2.2046 | 35.274 | 1,000 | 0.1575 |
| 1 pound (lb) | 0.4536 | 1 | 16 | 453.6 | 0.0714 |
| 1 ounce (oz) | 0.02835 | 0.0625 | 1 | 28.35 | 0.00446 |
| 1 gram (g) | 0.001 | 0.002205 | 0.03527 | 1 | 0.000157 |
| 1 stone (st) | 6.3503 | 14 | 224 | 6,350.3 | 1 |
| Conversion | Formula | Example |
|---|---|---|
| Celsius → Fahrenheit | °F = °C × 9/5 + 32 | 100°C → 212°F |
| Fahrenheit → Celsius | °C = (°F − 32) × 5/9 | 32°F → 0°C |
| Celsius → Kelvin | K = °C + 273.15 | 0°C → 273.15 K |
| Kelvin → Celsius | °C = K − 273.15 | 373.15 K → 100°C |
| Fahrenheit → Kelvin | K = (°F − 32) × 5/9 + 273.15 | 212°F → 373.15 K |
| Kelvin → Fahrenheit | °F = (K − 273.15) × 9/5 + 32 | 0 K → −459.67°F |
| From | To liters | To US gal | To US cups | To ml | To fl oz |
|---|---|---|---|---|---|
| 1 liter (L) | 1 | 0.2642 | 4.2268 | 1,000 | 33.814 |
| 1 US gallon | 3.7854 | 1 | 16 | 3,785.4 | 128 |
| 1 US cup (240 ml) | 0.2366 | 0.0625 | 1 | 236.6 | 8 |
| 1 milliliter (ml) | 0.001 | 0.000264 | 0.004227 | 1 | 0.033814 |
| 1 US fluid oz | 0.02957 | 0.007813 | 0.125 | 29.574 | 1 |
| 1 US pint (pt) | 0.4732 | 0.125 | 2 | 473.2 | 16 |
| 1 UK gallon | 4.5461 | 1.2009 | 19.215 | 4,546.1 | 153.72 |
Here are the unit conversions people search for most often:
Whether you are adapting a recipe from a US cookbook (which uses cups and Fahrenheit) to metric, checking whether a parcel weight is under an airline's limit, or comparing fuel efficiency between a US mpg and European L/100km figure, having an accurate and instant converter on hand saves time and prevents costly mistakes.
1 meter equals 3.28084 feet. Conversely, 1 foot equals 0.3048 meters. This conversion is essential for height comparisons between the US and metric countries.
Multiply by 9/5 (1.8) and add 32. So 20°C × 1.8 + 32 = 68°F. For a quick mental estimate, double the Celsius value and add 30 — this gives you within about 2°F for common temperatures.
1 kilogram equals 2.20462 pounds. To convert lbs to kg, divide by 2.20462. For a quick mental calculation: kg × 2.2 ≈ lbs, and lbs ÷ 2.2 ≈ kg.
1 US gallon equals 3.78541 liters. The UK (imperial) gallon is slightly larger: 4.54609 liters. Always check which gallon type is meant — the difference is about 20%.
100 kilometers equals 62.1371 miles. The conversion factor is 1 km = 0.621371 miles. A handy rule of thumb: multiply km by 0.6 for a quick approximation.
1 liter equals approximately 4.22675 US cups (240 ml each). 1 US cup is exactly 236.588 ml. Note: UK metric cups (250 ml) differ slightly from US cups.
Yes — BreezeCalc's unit converter is completely free, works in your browser with no signup, no ads blocking the results, and no data sent to any server. All calculations happen locally.
0 Kelvin (absolute zero) equals −273.15°C or −459.67°F. It is the lowest possible temperature — the point at which all thermal motion stops. It has never been fully achieved in practice, though scientists have come within billionths of a degree.