Convert Arabic numbers to Roman numerals and back. Supports 1–3999 with symbol breakdown, reference table, and copy buttons — all in your browser.
Also searched as: roman numeral converter · number to roman numerals · roman numerals translator · convert to roman numerals online
MMXXVI
2026
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
| Subtractive pairs | |
|---|---|
| IV | 4 |
| IX | 9 |
| XL | 40 |
| XC | 90 |
| CD | 400 |
| CM | 900 |
Step-by-step guide to get the most from this tool
Enter a number from 1 to 3999 on the left to see the Roman equivalent and breakdown.
Type a Roman numeral on the right to decode it to a decimal number.
Check the symbol table and subtractive pairs for quick lookups.
Use the copy buttons beside each output to paste elsewhere.
What makes this tool stand out
Convert Arabic ↔ Roman instantly.
See how each Roman symbol builds the number.
Basic symbols and subtractive pairs.
Copy Roman or Arabic output.
Encode inputs in a shareable URL.
Pure client-side logic — no server.
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Quick answers to common questions
Standard Roman numerals from 1 to 3999. This matches classical notation without vinculum (overline) extensions for larger values.
A smaller symbol before a larger one is subtracted — for example, IV is 4 (5 − 1) and CM is 900 (1000 − 100).
Only combinations that follow classical rules are accepted — no more than three identical symbols in a row, and only standard subtractive pairs like IV, IX, XL, XC, CD, and CM.
When converting Arabic to Roman, the breakdown shows each symbol chunk used to build the result, such as M=1000 and CM=900.
Yes. All conversion runs entirely in your browser with no network requests.
Your data is processed entirely in your browser. Nothing is sent to any server.