The 7 symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1,000 |
How to Read Roman Numerals
To read a Roman numeral, go from left to right and add the value of each letter, except that a smaller letter before a larger one is subtracted. The seven letters are I (1), V (5), X (10), L (50), C (100), D (500) and M (1,000). XIV is 10 + 4, so it is 14.
Example: XIV
14 = 10 + 4 = X + IV
The add rule
When a letter is followed by letters of equal or lower value, add them all. VI is 5 + 1 = 6, XII is 10 + 1 + 1 = 12, and MDC is 1000 + 500 + 100 = 1600.
The subtract rule
A smaller letter placed before a larger one is subtracted. Only six pairs are used: I before V or X, X before L or C, and C before D or M.
- IV = 4
- IX = 9
- XL = 40
- XC = 90
- CD = 400
- CM = 900
The repeat rule
I, X, C and M can repeat up to three times in a row: III is 3, XXX is 30 and MMM is 3,000. V, L and D are never repeated. That is why 4 is IV, not IIII, and 40 is XL, not XXXX.
Why clocks often show IIII
Many clock and watch faces show 4 as IIII, while others use IV. Both forms appear on clock faces, and several explanations are offered for IIII, so treat it as a design tradition rather than a rule. Outside clock faces, 4 is written IV.
There is no zero
Roman numerals have no symbol for zero. The system starts at I for 1, so the converter shows a message if you enter 0, and a date in Roman numerals has no leading zeros: the 5th of the month is V.
Large numbers and the bar
A bar over a numeral multiplies it by 1,000, so V with a bar is 5,000. Without the bar, standard Roman numerals stop at 3,999 (MMMCMXCIX). The page on large Roman numerals converts 4,000 to 3,999,999.
Common mistakes
- IC for 99: a smaller letter can be subtracted only from the next two larger letters, so 99 is XCIX.
- IL for 49: write 40 and 9 separately, so 49 is XLIX.
- MIM for 1999: write 1000, 900, 90 and 9, so 1999 is MCMXCIX.
- VX for 5: V is never subtracted, and 5 is simply V.
- VV for 10: V never repeats, and 10 is X.
- IIII for 4 outside a clock face: the standard form is IV.
Roman numerals are not a code for the alphabet: they stand only for numbers, so there is no Roman numeral for a letter or a name.
How to write a number in Roman numerals
- Split the number into place values. Break the number into thousands, hundreds, tens and ones, for example 1994 is 1000 + 900 + 90 + 4.
- Write the thousands. Write one M for each thousand: 1000 is M.
- Write the hundreds, tens and ones. Use the pattern for each place: 900 is CM, 90 is XC and 4 is IV.
- Join the parts from left to right. Put the parts together from largest to smallest: M + CM + XC + IV is MCMXCIV.
- Check the repeat rule. Make sure no letter repeats more than three times in a row and V, L and D appear only once.
Practice: 10 examples with answers
How to read a numeral, step by step
- Split the numeral into letters. Write the numeral as separate letters, for example XLIX as X, L, I, X.
- Group any subtractive pair. Join a smaller letter that stands before a larger one into a pair: XL and IX.
- Write each group's value. XL is 40 and IX is 9.
- Add the values. Add the values from left to right: 40 + 9 = 49.
- Check the result. Type the numeral into the converter to confirm the number.
| Numeral | Answer |
|---|---|
| VII | 7 |
| XIV | 14 |
| XXIX | 29 |
| XLIX | 49 |
| XCIV | 94 |
| CDXLIV | 444 |
| CMXCIX | 999 |
| MCMXCIV | 1994 |
| MMXXVI | 2026 |
| MMMCMXCIX | 3999 |
Check any other numeral with the Roman numeral converter, or look one up in the Roman numeral chart.
Questions and answers
What are Roman numerals?
Roman numerals are a number system that uses letters instead of digits. Seven letters carry the values: I is 1, V is 5, X is 10, L is 50, C is 100, D is 500 and M is 1,000. Numbers are built by adding and subtracting those values, so XIV is 14 and MCMXCIV is 1994.
How do you read Roman numerals?
Read from left to right and add the letters, but subtract a letter that stands before a bigger one. In XLII, XL is 40 (50 minus 10) and II is 2, so the total is 42. Work in groups, write down each value, add them up, and check the answer with the converter.
What are the rules for Roman numerals?
There are three rules. Add letters of equal or lower value that follow a letter. Subtract only I before V or X, X before L or C, and C before D or M. Repeat I, X, C and M up to three times in a row, but never repeat V, L or D. That is why 4 is IV, not IIII.
What are the Roman numeral symbols and their values?
There are seven Roman numeral symbols: I is 1, V is 5, X is 10, L is 50, C is 100, D is 500 and M is 1,000. Every other number is made by combining them. The symbol table at the top of this page lists all seven, and the converter shows how any number is built from them.
What is the Roman numeral for zero?
There is no Roman numeral for zero. Standard Roman numerals start at I for 1 and have no symbol for nothing, so the converter shows a message when you enter 0. In a Roman numeral date this means no leading zeros: the 5th is written V, not 05. A year such as 2000 is simply MM.
How do you write numbers in Roman numerals?
Split the number into thousands, hundreds, tens and ones, write each part in Roman numerals, and join them from largest to smallest. For 1994 that is M for 1000, CM for 900, XC for 90 and IV for 4, giving MCMXCIV. Never repeat a letter more than three times in a row.
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