Unit Converter: Length, Weight, Volume and Temperature
A unit converter translates a value from one measurement unit to another using an exact conversion factor. It is the everyday fix for recipes, shipping, DIY, travel and technical work that crosses the metric and imperial systems.
Conversion factors worth memorising
- 1 inch = 2.54 cm exactly; 1 foot = 0.3048 m; 1 mile = 1.60934 km.
- 1 kg = 2.20462 lb; 1 ounce = 28.3495 g.
- 1 litre = 0.264172 US gallons = 0.219969 imperial gallons.
- °F = °C × 9/5 + 32; °C = (°F − 32) × 5/9.
Watch the gallon and the ton
A US gallon is 3.785 litres and an imperial gallon is 4.546 litres — a 20% difference that also flows through to pints, quarts and fluid ounces. Similarly, a metric tonne is 1,000 kg, a US short ton is 907 kg and a UK long ton is 1,016 kg. Always confirm which system a figure came from.
Weight versus volume in cooking
Cup measurements are volume, not weight, so a cup of flour and a cup of sugar have different masses. A cup of all-purpose flour is roughly 120-125 g while a cup of granulated sugar is about 200 g. Baking, where ratios matter, is much more reliable in grams — which is why professional recipes are written by weight.
Key takeaways — Unit Converter
- Convert with exact factors; rounding early compounds error.
- US and imperial liquid measures differ — check the origin of the recipe or spec.
- Use weight rather than volume for accurate baking and chemistry.