Unit converter
Length, weight, volume, temperature and more.
Roman numeral converter
Convert numbers to Roman numerals and Roman numerals back to numbers.
Your files stay on your device
How it works
- 1Choose Number to Roman or Roman to number.
- 2Type or paste your input. One value per line works too.
- 3Read the result.
- 4Copy it.
What the options do
- Number to Roman
- Whole numbers from 1 to 3999.
- Roman to number
- Standard numerals made from I, V, X, L, C, D and M, in either case.
Privacy
Everything is calculated in your browser. Nothing you enter is sent to a server.
Questions people ask
Why does it stop at 3999?
Standard Roman numerals have no repeated M beyond three, so 4000 needs a bar over the numeral, an extension this tool does not use.
Is there a zero?
No. The Romans had no symbol for zero. Some medieval writers used the word nulla.
Why is 4 written IV and not IIII?
Standard modern writing uses subtraction: a smaller symbol before a larger one is subtracted. Some clock faces still use IIII for the look of it.
Why does it say my numeral is invalid?
Something like IC or VX breaks the rules. The tool accepts only the standard forms, for example 99 is XCIX, not IC.
What is it used for today?
Chapter and film numbers, clock faces, outlines, event names such as Super Bowl LX, and building dates.