Text & language
Roman Numeral Converter
2026 = MMXXVI: conversion both ways, with strict validation built in.
A date to engrave, chapters to number, a movie-credits year to decode, a Super Bowl edition to make sense of: Roman numerals never really left our lives. Type a number between 1 and 3999 and its Roman form appears instantly; type a Roman numeral — upper or lower case, it does not matter — and the tool detects the direction on its own and returns the Arabic value. Validation is strict: IIII, IXX or VX are flagged as invalid rather than guessed at, which also makes this a handy checker for Roman spelling. Free, immediate, no sign-up — and reliable all the way to MMMCMXCIX.
How does it work?
- Type a number (1 to 3999) or a Roman numeral — the direction is detected automatically.
- The conversion appears live; malformed Roman numerals are flagged.
- Copy the result with one click.
Frequently asked questions
How do you write 2026 in Roman numerals?
2026 is MMXXVI: MM (2000) + XX (20) + VI (6). Likewise 2025 is MMXXV and 1999 is MCMXCIX — M, then CM (900), XC (90) and IX (9). The rule: add symbols left to right, and a smaller symbol placed before a larger one subtracts (IV = 4, IX = 9, XL = 40, CM = 900).
Why is IIII rejected when clock faces use it?
Standard notation writes 4 as “IV”: never more than three identical symbols in a row. The IIII on watch dials is a deliberate aesthetic exception — it visually balances the VIII sitting opposite. This tool enforces the canonical form, the one expected in a text, an inscription or an exam.
Why the limit of 3999?
Because with the seven basic symbols (I, V, X, L, C, D, M) and the three-repetitions rule, the largest writable number is MMMCMXCIX = 3999. The Romans wrote bigger numbers with a bar over the letters (an overlined V meant 5000) — a typographic convention that is hard to reproduce in plain text today.
Do Roman numerals have a zero?
No. The Roman system is purely additive and never needed one: where we would write zero, they simply wrote nothing. Zero as a digit reached Europe in the Middle Ages with Hindu-Arabic numerals — one of the reasons that system eventually won out for arithmetic.