Unit converter
Convert values between length, mass, volume, area, speed, pressure and energy units.
Unit converter
Paste a value, or a whole list of them, and this tool converts each one between units of the same quantity: length, mass, volume, area, speed, pressure or energy. It reads the number and the unit written right after it — "5 km", "2.5kg", "100 mph" — so you can convert a list of measurements in one pass instead of looking up each figure separately.
Pick the quantity you're working with, then the source and target units, which cover both metric (km, kg, l, kPa) and imperial or US customary units (mi, lb, gal, psi). Set "To unit" to a specific unit for a single conversion, or to "All units in category" to see a value expressed in every unit of that quantity at once. "Decimal places" sets the rounding precision, and "Detect unit in text" lets the tool read the unit from each line itself, rather than assuming every value is in the "From unit" you picked — useful when a list already mixes several labeled measurements.
With "Keep original line" on, the source line stays untouched and the conversion is added on the line below it; turn it off to replace each line with just the result. A line with no recognizable unit next to its number is left alone, and one with a word that looks like a unit but isn't — a typo, or a unit from a different quantity — is flagged rather than silently converted wrong. Output numbers are formatted for your language's decimal and thousands separators.
Everything runs locally in your browser — no value is sent to a server, so it's safe to convert figures from private documents. Copy the result, download it as a .txt file, or send the output back into the input to convert again in another unit.