Roman Numeral Converter
Type a number to get its Roman numeral, or type a Roman numeral to get the number. The converter detects the direction for you, works for every value from 1 to 3999, and rejects malformed numerals such as IIII or VX instead of guessing. A symbol reference is included for quick lookups.
The direction is detected automatically: digits convert to a Roman numeral, letters convert back to a number.
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Student ToolsAbout the Roman Numeral Converter
Roman numerals are built from seven letters: I for 1, V for 5, X for 10, L for 50, C for 100, D for 500, and M for 1,000. Letters are normally added from largest to smallest, so 8 is VIII, but a smaller letter placed before a larger one is subtracted, so 4 is IV, 9 is IX, 40 is XL, 90 is XC, 400 is CD, and 900 is CM. This converter follows the standard form, which is why the range ends at 3999 (MMMCMXCIX): there is no standard symbol for 5,000 or higher, and a letter is never repeated more than three times in a row. Some historical uses, such as IIII on clock faces, are traditional variants and are rejected here so that results stay consistent with the standard rules. Handy examples include 2026 as MMXXVI and 1994 as MCMXCIV. The conversion is instant and runs entirely in your browser.
What is 2026 in Roman numerals?▾
2026 is MMXXVI: MM is 2,000, XX is 20, and VI is 6.
Why does the converter stop at 3999?▾
Standard Roman numerals have no symbol above M (1,000) and never repeat a letter more than three times in a row, so the largest standard numeral is MMMCMXCIX, which is 3999.
Why is IIII rejected as a Roman numeral?▾
The standard way to write 4 is IV. IIII appears on some clock faces as a traditional variant, but it is not part of the standard rules, so this converter treats it as invalid.