Convert between Arabic numbers and Roman numerals
Year
2024 → MMXXIV
Small number
9 → IX (subtractive notation).
From Roman
XLII → 42.
What range is supported?
1–3999 for numbers to Roman; common Roman numerals back to Arabic.
Do you allow lowercase?
Yes, input is uppercased for conversion.
Is the calculation local?
Yes. Everything runs in your browser; no data is stored.