Roman Numeral Converter
Convert numbers to Roman numerals (I, V, X, L, C, D, M) and vice versa. Perfect for historical dates, outlines, or learning.
Step 1: Enter Value
How it works
Type in either field — the other updates instantly. Roman numerals use I=1, V=5, X=10, L=50, C=100, D=500, M=1000.
Step 2: Options
Did you know?
The largest number you can write with standard Roman numerals is 3999 (MMMCMXCIX). For larger numbers, a bar above multiplies by 1000, but this converter follows classic rules.
Conversion Result
Converted value
📋 Conversion breakdown
Common Roman numerals
| Number | Roman | Number | Roman |
|---|---|---|---|
| 1 | I | 50 | L |
| 2 | II | 100 | C |
| 3 | III | 500 | D |
| 4 | IV | 1000 | M |
| 5 | V | 1990 | MCMXC |
| 9 | IX | 2025 | MMXXV |
| 10 | X | 3999 | MMMCMXCIX |
Roman numeral rules
Basic symbols
I=1, V=5, X=10, L=50, C=100, D=500, M=1000
Subtraction rule
A smaller numeral before a larger means subtract: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900.
No more than three in a row
You write 4 as IV (not IIII), 40 as XL, etc.
Conversion method
Split number into thousands, hundreds, tens, units and translate each group.
Example: 2025 = 2000 (MM) + 20 (XX) + 5 (V) = MMXXV.
Roman numerals got you stuck?
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