Convert length, weight, volume and temperature between US customary and metric units — the everyday conversions in one place. ✓ Length · Weight · Volume · Temp
| US unit | Metric | Reverse |
|---|---|---|
| 1 inch | 2.54 cm | 1 cm = 0.394 in |
| 1 foot | 30.48 cm | 1 m = 3.281 ft |
| 1 yard | 0.914 m | 1 m = 1.094 yd |
| 1 mile | 1.609 km | 1 km = 0.621 mi |
| US unit | Metric | Reverse |
|---|---|---|
| 1 ounce | 28.35 g | 1 g = 0.035 oz |
| 1 pound | 0.454 kg | 1 kg = 2.205 lb |
| 1 stone (14 lb) | 6.35 kg | 1 kg = 0.157 st |
| 1 US ton (2,000 lb) | 907.2 kg | 1 tonne = 1.102 US ton |
| US unit | Metric | Reverse |
|---|---|---|
| 1 fluid ounce | 29.57 ml | 1 litre = 33.8 fl oz |
| 1 cup | 240 ml | 1 litre = 4.17 cups |
| 1 pint | 473 ml | 1 litre = 2.11 pt |
| 1 US gallon | 3.785 litres | 1 litre = 0.264 gal |
°C = (°F − 32) × 5/9 · °F = (°C × 9/5) + 32
| Description | Fahrenheit | Celsius |
|---|---|---|
| Freezing | 32 °F | 0 °C |
| Cool day | 50 °F | 10 °C |
| Room temp | 68 °F | 20 °C |
| Warm day | 86 °F | 30 °C |
| Body temp | 98.6 °F | 37 °C |
| Boiling | 212 °F | 100 °C |
The United States is the main country still using US customary units (inches, pounds, gallons, Fahrenheit) in daily life, while nearly everywhere else — the UK, Canada, Australia, the UAE and Europe — uses the metric system (centimetres, kilograms, litres, Celsius). This chart puts the everyday conversions side by side so you can switch between them instantly, whether you're travelling, cooking, studying or shopping online across borders.
The key numbers to remember: 1 inch = 2.54 cm, 1 pound = 0.454 kg, 1 US gallon = 3.785 litres, and for temperature, subtract 32 and multiply by 5/9 to go from Fahrenheit to Celsius. For any other unit or an exact figure, use our length, weight, volume and temperature converters.
US customary units have been legally defined in terms of metric ones since 1959, which means many everyday conversions are exact rather than approximate. One inch is precisely 2.54 centimetres, one pound is exactly 0.45359237 kilograms, and one US gallon is exactly 3.785411784 litres. Rounding these is a choice about presentation, not a limit on accuracy.
A few conversions genuinely are not exact, and temperature is the clearest case: Celsius and Fahrenheit have different zero points, so the conversion needs an offset as well as a ratio and cannot be reduced to a single multiplier.
The traps here are the units that share a name and differ in size. A US liquid gallon is about 3.785 L while an imperial gallon is about 4.546 L — a 20% difference that quietly wrecks fuel-economy comparisons between American and British figures. Dry measure is a third system again, with its own gallon of roughly 4.405 L. A quantity in "gallons" is ambiguous until you know which gallon is meant.