Roman Numeral Converter
Convert numbers 1–3999 to Roman numerals, and valid Roman numerals back to numbers.
Quick answer
- Formula: Greedy decomposition: 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)
- Worked example — Number: 1,994 (full example below).
Roman Numeral Converter
| Number | 1,994 |
| Roman numeral | MCMXCIV |
| Summary | 1994 = MCMXCIV |
1994 = MCMXCIV: M (1000) + CM (900) + XC (90) + IV (4) — the year style seen in film credits.
Convert in both directions. Numbers from 1 to 3999 become Roman numerals using the standard subtractive forms (IV for 4, IX for 9, XL for 40, CD for 400), so 1994 = MCMXCIV.
Converting back is strict: the text is parsed and then recomposed, and only accepted if it matches the canonical form exactly — so IIII, VX and IC are rejected, keeping clocks, copyright dates and Super Bowl numbers honest.
The formula
Worked example
1994 = MCMXCIV: M (1000) + CM (900) + XC (90) + IV (4) — the year style seen in film credits.
The example is pre-loaded in the result panel — press Calculate with your own numbers to replace it.
Frequently asked questions
Why does the range stop at 3999?
Standard Roman numerals have no symbol above M (1000) and never repeat a symbol more than three times, so MMMCMXCIX (3999) is the largest standard value. Larger numbers historically used a bar (vinculum) over the numeral.
Why is IIII rejected if some clocks use it?
IIII is a traditional clockmaker's exception, but the standard subtractive form for 4 is IV. This converter validates against the canonical form so results are unambiguous.
How do you read MCMXCIV?
Left to right with subtraction when a smaller symbol precedes a larger one: M=1000, CM=900, XC=90, IV=4 — total 1994.
Category: Unit Conversions calculators
Sources & methodology
This calculator applies the formula shown on this page exactly as written, using the standard definitions for its inputs. Results are computed from the values you enter — no data is stored — and are rounded only for display.
Content last reviewed by CalcHub Editorial.
Embed this calculator on your site
Free to use with attribution — paste the snippet below and the calculator appears on your page, with a link back to CalcHub.