Unit Converter
Convert length, weight, temperature, volume, and speed units. Your work stays on this device whenever possible.
How to use Unit Converter
- Pick a category in the Measurement selector; the page offers eleven, including Length, Temperature, Digital storage, Energy, Pressure and Angle.
- Type the number to convert into the Value field, which accepts decimals and negatives (useful for temperatures).
- Choose the source in From and the target in To; both lists refill with the units for the chosen category, and To starts on the second entry.
- Set the Decimals selector to 2, 4, 6 or Maximum (10 decimals), then press "Convert".
- Press "Swap ⇄" to reverse the direction and recompute at once, and read the line beneath the answer that states the per-unit factor.
Worked example
Choose Mass, enter 5 in Value, set From to Stone and To to Kilograms, and select 4 decimals. The tool prints 5 Stone = 31.7515 Kilograms, then the factor line 1 Stone = 6.35029318 Kilograms. Check: 5 × 6.35029318 = 31.7514659, which rounds to 31.7515 at four decimals.
When to use this tool
- Turning a UK body weight given in stone into kilograms for a fitness form.
- Checking a tire pressure printed in PSI against a European gauge that reads in bar.
- Converting an oven or lab temperature from Fahrenheit to Kelvin for a science worksheet.
Important limitations
Unit conversions are mathematical, but kitchen measures, historical units, and US versus imperial volumes can use different definitions. Confirm the labelled unit system.
Frequently asked questions
Why can't I convert kilograms to litres?
Units are grouped by category, and each category has its own From and To lists. Mass, volume and length cannot be mixed because turning weight into volume needs the density of the specific substance, which the tool does not ask for.
How does the tool handle temperature differently?
Temperature does not use a single multiplier. Values pass through Celsius using offset formulas, and Celsius, Fahrenheit, Kelvin and Rankine are all available. That is why the result line says which scales were used rather than showing a per-unit factor.
Are kilobytes and kibibytes the same here?
No. Kilobyte, megabyte and gigabyte use powers of 1,000, while kibibyte, mebibyte and gibibyte use powers of 1,024. Picking the wrong family explains why a drive's advertised capacity looks smaller in an operating system.
What length of year does the Time category use?
A year is treated as a Julian year of 365.25 days (31,557,600 seconds), and a month is not offered at all because months vary in length. For exact calendar spans use the date difference tool instead.
Why does the answer show fewer decimals than I chose?
The result is formatted so trailing zeros are dropped. Selecting 4 decimals for a value that is exactly 12.5 will display 12.5. Very small results can still round to 0 at the chosen precision, so raise the setting.