One tool, four everyday conversions
This converter covers the categories people reach for most: length, weight, temperature and volume. Length, weight and volume are simple ratios — every unit is defined relative to a base unit, so converting is just multiplying and dividing. Temperature is different, because the scales don't share a zero point, so the tool applies the proper Celsius, Fahrenheit and Kelvin formulas rather than a single factor.
Metric and imperial, side by side
Because it mixes metric and imperial units in each category, it's handy when a recipe is in cups but your jug is in millilitres, when a package lists pounds but you think in kilograms, or when a plan is in feet and you build in metres. Pick any pair and read the result instantly.
Accurate conversion factors
The factors used are the exact internationally defined ones — an inch is exactly 2.54 cm, a pound is 453.59237 g, a US gallon is 3.785411784 L — so results are precise, not rounded approximations.
Frequently asked questions
What's the difference between US and UK gallons?
They're different sizes: a US gallon is about 3.79 litres while a UK (imperial) gallon is about 4.55 litres. Pick the one that matches your source.
Why isn't temperature just a factor?
Because the scales have different zero points. Converting needs a shift as well as a scale change, which is why the tool uses the full formulas for °C, °F and K.