Roman Numerals Converter
Free Roman numerals converter — convert numbers to Roman numerals or Roman numerals to numbers instantly. Supports 1–3999, bulk conversion, and copy. No signup.
| Symbol | Value | Symbol | Value |
|---|---|---|---|
| I | 1 | L | 50 |
| IV | 4 | XC | 90 |
| V | 5 | C | 100 |
| IX | 9 | CD | 400 |
| X | 10 | D | 500 |
| XL | 40 | CM | 900 |
| M | 1000 |
About Roman Numerals Converter
The Roman Numerals Converter translates any number between 1 and 3999 into its Roman numeral form — or decodes any Roman numeral back into a plain digit — as you type. Just enter a value and the result appears instantly alongside a full step-by-step breakdown showing exactly how the conversion works.
Roman numerals are still in everyday use: book and chapter headings, movie sequel titles (Rocky IV, Star Wars Episode IX), Super Bowl numbering, clock and watch faces, copyright years on films and broadcasts, numbered monarchs and popes, and architectural engravings. Being able to read and write them fluently saves time and prevents embarrassing errors in published work.
The breakdown panel shows the conversion in parts. Type 2024 and you’ll see 2000 = MM, 20 = XX, 4 = IV, total MMXXIV. Type MCMXCIX and you’ll see M = 1000, CM = 900, XC = 90, IX = 9, total 1999. This makes the tool useful not just for looking up a value, but for understanding how Roman numeral arithmetic actually works.
The notation uses seven base symbols — I, V, X, L, C, D, M — combined by additive and subtractive rules. A smaller value placed before a larger one is subtracted: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900. All other combinations are additive. The quick reference table at the bottom of the tool lists every symbol and its value for easy lookup.
The rules in one paragraph
Seven symbols (I=1, V=5, X=10, L=50, C=100, D=500, M=1000), two rules. Same-or-smaller letters after a larger one are added (XIII = 13). A smaller letter before a larger one is subtracted, but only with these six valid pairs: IV, IX, XL, XC, CD, CM. So 999 is CMXCIX, not IM. For the full chart 1–100, common year conversions, the IIII-vs-IV clock convention, and the most common mistakes (especially on tattoos), see Roman Numerals Chart and Rules.
Everything runs in your browser with no server calls, no storage, and no signup required.
Frequently asked questions
Standard Roman numerals cover 1 to 3999 (I to MMMCMXCIX). Numbers outside this range cannot be represented in classical Roman numeral notation, and the tool will flag them accordingly.
Yes. Just type any Roman numeral — like XIV or MCMXCIX — directly into the input field. The tool auto-detects that it's a Roman numeral and instantly returns the Arabic digit equivalent with a full breakdown.
Yes. Every conversion includes a step-by-step breakdown showing each component and its value — for example, MMXXIV breaks down as MM = 2000, XX = 20, IV = 4. This makes it easy to understand the logic, not just get the answer.
Roman numerals appear in book chapters, movie sequels, clock faces, copyright years, Super Bowl numbers, monarchs and popes (e.g. Elizabeth II), outlines, and architectural cornerstones. Knowing how to read and write them is still practically useful.