Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers, from 1 to 3999.
MMXXVI
2,026
Roman numeral chart
This Roman numeral converter works in both directions: enter an ordinary number to get the Roman numeral, or paste a Roman numeral to get the value back. Conversion happens as you type and validates the input, so an invalid numeral like IIII or VX is flagged rather than silently accepted.
Roman numerals use seven letters: I (1), V (5), X (10), L (50), C (100), D (500) and M (1000). Values are added when written in descending order — XVI is 16 — and subtracted when a smaller symbol precedes a larger one, which is why 4 is IV and 900 is CM. Only I, X and C can be used subtractively, and never more than one at a time.
The standard system tops out at 3,999 (MMMCMXCIX) because there is no single symbol for 5,000 in the common notation; larger values historically used a bar over the numeral to multiply it by a thousand. This Roman numeral converter covers the standard 1–3999 range that Super Bowl numbers, book chapters, clock faces, film copyright dates and monarch names all use. Everything runs client-side — free, instant, no signup.
Roman numeral translation rules
Translating a Roman numeral is a left-to-right scan: add each symbol's value unless it is smaller than the symbol after it, in which case subtract it. MCMXCIV reads as 1000, then CM (900), then XC (90), then IV (4) — 1994.
Only I, X and C subtract, and only from the next two larger symbols: IV and IX, XL and XC, CD and CM. That rule is why 99 is XCIX and never IC.
Common conversions and dates
Years are where most people need this: 2026 is MMXXVI, 1999 is MMCMXCIX's neighbour MCMXCIX, and 1776 is MDCCLXXVI. Chapter numbers, clock faces, Super Bowl numbering and film copyright lines all use the same system.
The converter covers 1 to 3999 because standard Roman numerals have no symbol above M; larger values historically used an overbar to multiply by a thousand, which is not part of everyday usage.