Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers. Choose a direction, enter a whole number from 1 to 3999, or type a Roman numeral, and the converter shows the answer using standard subtractive notation. It is handy for reading clock faces, book chapters and outlines, movie sequels, copyright dates, and monuments that record years in Roman numerals.
Calculate
Default result: MMXXIV
Roman Numeral Converter · Result
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Result
toRoman × 2024 × MMXXIV
Reviewed by the calculators.dev team · Last updated 2026-06-23
How to calculate
Choose whether you are converting a number to a numeral or a numeral to a number. To build a numeral by hand, work from the largest value down: 2024 is M (1000) + M (1000) + X (10) + X (10) + IV (4), written MMXXIV. The subtractive pairs IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900) put a smaller letter before a larger one to mean subtraction.
To encode, greedily subtract the largest value whose symbol fits — M=1000, CM=900, D=500, CD=400, C=100, XC=90, L=50, XL=40, X=10, IX=9, V=5, IV=4, I=1 — appending its letters each time. To decode, add each letter's value, but subtract it when a smaller letter sits directly before a larger one (the IV/IX/XL/XC/CD/CM rule).
Example calculation
2024 in Roman numerals is MMXXIV: two thousands (MM), then twenty (XX), then four written subtractively as IV (one before five).
- result
- MMXXIV
Assumptions
- Standard Roman numerals represent the whole numbers 1 (I) through 3999 (MMMCMXCIX); there is no symbol for zero and no agreed standard form above 3999.
- Subtractive notation is used: 4 is IV (not IIII) and 9 is IX, so each numeral has exactly one canonical form.
- A letter never repeats more than three times in a row, which is why 40 is XL rather than XXXX.
Common mistakes
- Writing 4 as IIII or 9 as VIIII instead of the subtractive IV and IX.
- Repeating a letter four times, such as XXXX for 40, when the correct form is XL.
- Expecting a numeral for zero or for numbers above 3999 — standard Roman numerals do not define either.
Frequently asked questions
What is 2024 in Roman numerals?
2024 is MMXXIV: MM is 2000, XX is 20, and IV is 4 written subtractively.
Why is 4 written as IV and not IIII?
Standard Roman numerals use subtractive notation, so a smaller letter before a larger one means subtraction: IV is 5 − 1 = 4. The IIII form appears on some clock faces but is not the standard written form.
What is the largest number in Roman numerals?
Using standard letters, the largest value is 3999, written MMMCMXCIX. There is no standard single-letter symbol for larger values without adding overlines or other notation.
Is there a Roman numeral for zero?
No. The Roman numeral system has no symbol for zero; it represents only the positive whole numbers from 1 upward.