Unit Converter
Unit conversion is multiplication by a factor, with one important exception. Length, weight, volume, area and speed all convert by scaling, because zero means the same thing in every unit of that category. Temperature does not, because the scales have different zero points, so it needs an offset as well as a factor — which is why Celsius and Fahrenheit conversions are the ones people most often get wrong.
This converter handles six categories from one panel. Choose the category, then the unit you have and the unit you want, and enter the value. The result appears with the conversion factor stated, so you can see whether the answer is plausible rather than trusting it blindly. A quick check is to remember that a kilometre is about 0.62 miles, a kilogram is about 2.2 pounds, and a litre is about 0.26 US gallons.
Watch the metric-imperial traps that are not simple multiples. US and imperial gallons are different sizes, so a US gallon is about 3.79 litres and a UK gallon about 4.55. A US ton is 2,000 pounds while a metric tonne is about 2,204.6. An ounce can mean a mass unit or a fluid volume. Picking the right option matters more than the arithmetic.
The equivalence rows below the main result show the same value in several related units, which is often more useful than a single conversion. If you need a figure to act on — a shipping weight, a recipe measure, a distance — those common equivalents usually give you a way to sanity-check the number against everyday experience.
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How the math works
- Convert the input to the category's base unit by multiplying by the chosen unit's factor, then divide by the target unit's factor.
- Temperature is handled separately with explicit offset formulas rather than a factor, because the scales have different zero points.
- Each category's base unit is metres for length, kilograms for weight, litres for volume, square metres for area and metres per second for speed.
- The equivalence rows apply the same conversion to several other units in the chosen category for comparison.
Frequently asked questions
Why is temperature different from other conversions?
Is a US gallon the same as a UK gallon?
How many pounds are in a kilogram?
How do I convert miles to kilometres?
What is the difference between a metric tonne and a US ton?
Why do the equivalence rows show several units?
This calculator is an educational estimator. It is not financial, medical, tax, or legal advice, and it does not account for fees, local rules, or your personal circumstances. Confirm decisions with a qualified professional.