Roman Numeral Converter
Last updated: June 2026 · Free · No sign-up required
Frequently Asked Questions
What are the basic Roman numeral symbols?
The key Roman numerals are: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).
Why is the conversion limit set to 3,999,999?
Standard Roman numerals cannot easily represent values of 4,000 or greater without special symbols like overlines (vinculum). In standard modern typing, 3,999 (MMMCMXCIX) is the maximum, but extended systems allow representing higher numbers using combinations of M.
How does subtraction work in Roman numerals?
When a smaller numeral is placed before a larger numeral, it is subtracted. For example, IV represents 5 - 1 = 4, and IX represents 10 - 1 = 9.
Quick reference
Roman numeral symbols:
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1,000 |
edit_note What you need
Have your numbers ready before you start. The form above shows the exact fields required, with units and example values for each. Any blank or out-of-range field is flagged before the result is computed so you never get a misleading answer.
function How it computes
The roman numeral converter applies the published reference formula and rounds the result to a useful precision. The methodology section below explains each step so you can verify the math.
verified Trusted source
Reference values and constants come from an authoritative source. Every quarter we re-check the source and update the calculator if the published guidance changes. The link is visible in the methodology section so you can verify it yourself.
tips_and_updates Read it like this
Read the headline number first, then open the breakdown card to see how each input contributed. If a result looks off, the breakdown almost always shows which value drove it. Adjust that input and recalculate — the answer updates instantly.
Interpretation guide
Examples:
| Number | Roman numeral |
|---|---|
| 4 | IV |
| 9 | IX |
| 40 | XL |
| 90 | XC |
| 2024 | MMXXIV |
| 2026 | MMXXVI |
Formula & methodology
Formula: Add symbols left to right; a smaller symbol before a larger one is subtracted (IV = 4, IX = 9)
Roman numerals combine seven letters using additive and subtractive rules. Symbols are written largest to smallest and added, but when a smaller value precedes a larger one it is subtracted (IV = 4, CM = 900). Only I, X, and C are used as subtractive prefixes, and no symbol repeats more than three times. The converter applies these rules in both directions and handles a vinculum (overline) for very large numbers.
Frequently asked questions
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