Roman Numeral Conversion Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/5/2026
To convert a number to Roman numerals, symbols (M=1000, D=500, C=100, L=50, X=10, V=5, I=1) are added from largest to smallest, using subtractive notation for certain values (IV for 4, IX for 9...). The year 1994 is written MCMXCIV.
Explanation
Roman numerals use seven basic symbols (I=1, V=5, X=10, L=50, C=100, D=500, M=1000) combined according to precise rules to represent any number from 1 to 3999. The general rule is to place symbols side by side from largest to smallest, adding their values (VI = 5+1 = 6). But to avoid repeating the same symbol more than three times in a row (IIII would have been hard to read for 4), Roman numerals also use subtractive notation: a symbol of lower value placed just before a symbol of higher value means it should be subtracted (IV = 5−1 = 4, IX = 10−1 = 9, XL = 50−10 = 40, XC = 90, CD = 400, CM = 900). The year 1994 nicely illustrates this principle by combining several subtractive forms: MCMXCIV breaks down into M (1000) + CM (900) + XC (90) + IV (4) = 1994. This calculator is limited to the 1-3999 range, the limit of standard Roman notation with these seven symbols: beyond that, the Romans used a bar above a symbol to multiply it by 1000, a convention less standardized today and outside the scope of this calculator. Roman numerals are still used today to number centuries, monarchs and popes (Louis XIV, Elizabeth II), chapters in some books, or the closing credits of some films.
Example: converting 1994
Inputs
Number: 1994.
Calculation
1994 = 1000 (M) + 900 (CM) + 90 (XC) + 4 (IV), that is M + CM + XC + IV = MCMXCIV.
Result
1994 is written MCMXCIV in Roman numerals.
Frequently asked questions
Why is 4 written IV and not IIII?
The IIII notation (the symbol I four times) was used in ancient Rome and remains visible on some traditional clock faces by aesthetic convention, but the modern standardized rule limits repetition of the same symbol to a maximum of three consecutive occurrences. Beyond that, subtractive notation (IV for 4, rather than IIII) is used to stay more concise and quicker to read.
Why does this calculator stop at 3999?
Because 3999 (MMMCMXCIX) is the largest number representable with the seven standard symbols without repeating M more than three times. Beyond 3999, historical Roman notation used a horizontal bar above a symbol to multiply its value by 1000 (a convention called vinculum notation), but it isn't universally standardized and remains outside the scope of this calculator.
Where can Roman numerals still be seen today?
They're still commonly used to number centuries (the 21st century), monarchs and popes of the same name (Louis XIV, John Paul II), certain book chapters or theater acts, the closing credits of films and TV series (sometimes indicating the production year), or certain clock and watch faces by aesthetic tradition.