900 in Roman Numerals
The number 900 is written as CM in Roman numerals.
Step-by-Step Breakdown
- Start with the largest Roman symbol that fits into 900.
- Subtract its value and repeat until nothing remains.
- Each symbol group above represents one subtraction step.
- The result — CM — is the concatenation of all groups in order.
Nearby Numbers
| Number | Roman Numeral |
|---|---|
| 897 | DCCCXCVII |
| 898 | DCCCXCVIII |
| 899 | DCCCXCIX |
| 900 | CM |
| 901 | CMI |
| 902 | CMII |
| 903 | CMIII |
How Roman Numerals Work
Roman numerals are a numeral system originating in ancient Rome that uses combinations of letters from the Latin alphabet. The system remained the standard way of writing numbers in Europe well into the late Middle Ages, and is still used today for clock faces, Super Bowl numbering, book chapters, and formal documents.
The Seven Core Symbols
Additive and Subtractive Notation
When a smaller symbol appears before a larger one, it is subtracted. For example, IV = 4 (5 − 1) and IX = 9 (10 − 1). This subtractive rule applies only for the six pairs: IV, IX, XL, XC, CD, and CM. All other combinations are additive — symbols are simply summed from left to right.
Repetition Rules
The symbols I, X, C, and M may each be repeated up to three times in a row. V, L, and D are never repeated. This means 3 = III, 30 = XXX, and 3000 = MMM — but 4 is not IIII; it is IV.
Valid Range
Standard Roman numerals cover 1 through 3999. The number 3999 is MMMCMXCIX — the largest expressible without an overline extension. The number 1 is simply I.
Need to convert a different number, or convert a Roman numeral back to a number? Use the full converter — it includes a date-to-Roman mode for tattoos and a step-by-step breakdown for any value 1 through 3999.
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