Roman Numeral Converter

Convert numbers and Roman numerals instantly

This Roman numeral converter turns any number into Roman numerals and converts Roman numerals back into normal numbers. The result updates as you type and can be copied with one click — useful for dates, tattoos, book chapters, clock faces and homework.

How to use it

1. Choose Number → Roman or Roman → Number.
2. Type a number (for example 2026) or a numeral (for example MMXXVI).
3. Copy the result with the Copy button.

Numbers from 1 to 3,999,999 are supported. Values of 4,000 and above use the overline (vinculum) form, where a line over a letter multiplies it by 1,000 — for example V̄ = 5,000.

Roman numerals chart

Roman	Number	Roman	Number
I	1	XL	40
IV	4	L	50
V	5	XC	90
IX	9	C	100
X	10	CD	400
D	500	CM	900
M	1,000	V̄	5,000

Rules for writing Roman numerals

• Add when a smaller symbol comes after a larger one: VI = 5 + 1 = 6.
• Subtract when a smaller symbol comes before a larger one: IV = 5 − 1 = 4, XC = 100 − 10 = 90.
• Only six subtractive pairs are used: IV, IX, XL, XC, CD and CM.
• Repeat a symbol at most three times: III = 3, but 4 is IV, not IIII.
• V, L and D are never repeated and never written before a larger symbol.

Examples

• 2026 = MMXXVI (1000 + 1000 + 10 + 10 + 5 + 1)
• 2025 = MMXXV
• 2000 = MM
• 1999 = MCMXCIX (1000 + 900 + 90 + 9)
• 1990 = MCMXC
• 49 = XLIX (40 + 9)
• 14 = XIV

Frequently asked questions

How do you write a year in Roman numerals?

Split the year into thousands, hundreds, tens and ones, convert each part and join them. 1987 becomes M + CM + LXXX + VII = MCMLXXXVII. The converter does this for you.

Is there a Roman numeral for zero?

No. The Roman system has no symbol for zero, so the converter starts at 1.

What is the largest Roman numeral?

With standard letters the largest is MMMCMXCIX (3,999). Using the overline notation the converter goes up to 3,999,999.

Can I convert numerals with an overline back to numbers?

Roman → Number mode reads the seven standard letters I, V, X, L, C, D and M. Overline numerals are only produced in the Number → Roman direction.