Give the number
its Roman form.
Convert an integer to standard Roman numerals or decode a numeral back to a number. The page validates modern subtractive notation and keeps every conversion in this browser tab.
Roman numeral converter
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MMXXVI = 2,000 + 20 + 6
Modern subtractive pairs: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). Standard notation on this page stays between 1 and 3,999.
Why is 4 written as IV instead of IIII?
Standard modern notation uses subtractive pairs. IV means one before five, IX means one before ten, and the same pattern applies to XL, XC, CD, and CM.
What is the largest standard Roman numeral?
For the usual seven-symbol system, this page uses 3,999, written MMMCMXCIX. Larger values need a separate overline or historical convention, so they are flagged instead of guessed.
Does the converter accept lowercase?
Yes. Roman input is trimmed, uppercased, and checked against the canonical modern form. Malformed sequences such as IIII, VV, or IC are rejected.