Unit conversion is simple in theory and easy to get wrong in practice — a slipped decimal, the wrong direction, or rounding too early. For anything that matters, like a recipe, a dosage or an engineering figure, it is worth letting a tool carry the precision.
Round at the end, not the middle
The biggest source of conversion errors is rounding partway through a multi-step conversion. Each rounding nudges the answer, and the nudges stack up. Keep full precision until the final step, then round once to the number of decimals you actually need.
How to convert
- Open the unit converter.
- Choose the category (length, weight, temperature, and so on).
- Enter a value in one unit and read it in the other. Conversions happen instantly in your browser.
Temperature is not like the others
Most conversions are pure multiplication, but temperature has an offset: Celsius to Fahrenheit is × 9/5 then + 32, not just a multiply. That extra step is why doing it in your head so often goes wrong, and why a converter is safest for anything important.