Unit Converter
Convert any amount between units of length, weight, area, volume, data storage, duration, speed or temperature, with the factor table behind the number.
Fill in the values and calculate
The form sends itself back to this page — results print below, computed on the server.
No results yet: fill the form above and press Calculate.
About Unit Converter
One amount in, the same amount out, with every factor shown. Ratio units convert as a multiple of a shared base unit, so the factor between any pair comes from dividing one unit's factor by the other's.
Temperature is not a ratio, so it gets its own maths: every scale is taken through degrees Celsius first. The page also prints the whole factor table for the kind you picked, which is what makes odd pairs like acres to square feet trustworthy.
Questions about Unit Converter
Are the factors exact?
Within display rounding. The factors in the table are the international definitions (one inch is exactly 0.0254 metres), and the result is rounded to seven significant digits.
Why won't it mix kilograms and miles?
Units of different kinds cannot convert into each other without an extra fact, like a density for mass-per-volume. Pick two units of the same kind here.
What is the base unit of each kind?
It is named in the notes: metres, kilograms, square metres, cubic metres, bytes, seconds and metres per second. Every table entry is a multiple of that base, which is why the ratios are stable.
Bookmark and homescreen
- Press Ctrl+B now (or Cmd+B on macOS) to bookmark this page in your browser.
- Drag this link to your bookmarks bar and it will always open this tool: Unit Converter.
- On a phone: open in Chrome/Safari and use "Add to Home Screen" — the site ships a homescreen icon and manifest, so it installs like an app.
- Two addresses work:
https://useful-utilities.com/unit-converter/andunit-converter.useful-utilities.com. Copy whichever you prefer.