Convert between Roman numerals and Arabic numbers. Learn how Roman numerals work with step-by-step breakdowns.
Roman Numeral
MMXXIV
Enter a number between 1 and 3999
1
5
10
50
100
500
1000
4
9
40
90
400
900
1. Addition Rule
When a smaller numeral follows a larger one, add them: VI = 5 + 1 = 6
2. Subtraction Rule
When a smaller numeral precedes a larger one, subtract: IV = 5 - 1 = 4
3. Repetition Limit
I, X, C, M can repeat up to 3 times. V, L, D never repeat.
4. Subtraction Pairs
Only I (before V, X), X (before L, C), and C (before D, M) are subtracted.
Roman Numeral
MMXXIV
Quick-start with common scenarios
Test your skills with practice problems
Practice with 3 problems to test your understanding.
Roman numerals use letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Add values when equal or smaller follows larger (VI=6). Subtract when smaller precedes larger (IV=4, IX=9). Example: MCMLXXXIV = M(1000) + CM(900) + L(50) + XXX(30) + IV(4) = 1984. Maximum using standard notation is 3,999 (MMMCMXCIX).
Roman numerals are a numeral system originating in ancient Rome using combinations of letters (I, V, X, L, C, D, M) to represent numbers. Unlike positional systems like Arabic numerals, Roman numerals use additive and subtractive combinations. They are still used today for clocks, copyrights, movie releases, outlines, and formal numbering.
Roman numerals use letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Add values when equal or smaller follows larger (VI=6). Subtract when smaller precedes larger (IV=4, IX=9). Example: MCMLXXXIV = M(1000) + CM(900) + L(50) + XXX(30) + IV(4) = 1984. Maximum using standard notation is 3,999 (MMMCMXCIX).
Roman numerals are a number system from ancient Rome using letters: I (1), V (5), X (10), L (50), C (100), D (500), M (1000). Numbers are formed by combining these letters. They were used throughout the Roman Empire and are still used today for clocks, outlines, and dates.
Roman numerals are generally added left to right (VI = 5+1 = 6). However, a smaller numeral before a larger one means subtraction (IV = 5-1 = 4, IX = 10-1 = 9). Only I, X, and C can be used for subtraction, and only immediately before the next two larger values.
Standard Roman numerals go up to 3999 (MMMCMXCIX). For larger numbers, ancient Romans used a bar over the numeral to multiply by 1000 (V̄ = 5000). Some systems use different conventions for very large numbers.
IV (4) uses subtractive notation - placing I before V means 5-1=4. This was adopted for brevity. However, IIII is sometimes seen on clock faces (called "watchmaker's four") for visual balance and tradition.
No, Roman numerals have no symbol for zero. The Romans didn't have a concept of zero as a number. This is one reason why Roman numerals were eventually replaced by Arabic numerals (which include zero) for calculations.
Last updated: 2025-01-15
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Roman Numeral
MMXXIV