Number
24 in Roman numerals
24 is written XXIV
Type any other number or numeral below to convert it.
Above 3,999? Type the barred part in brackets, e.g. (IV)CC = 4,200.
How XXIV is built
Roman numerals are written one decimal place at a time, largest first.
- XXtens · 2X written 2 times: 2 × 10 = 20.
- IVones · 4I before V means 5 − 1 = 4. This saves writing IIII.
20 + 4 = 24
The pair IV uses subtraction: a smaller letter before a larger one is taken away from it. Only six pairs work this way: IV, IX, XL, XC, CD and CM. More on subtraction
Mistakes to avoid
- Not XXIIII (6 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today XXIV (4 letters) is the standard.
About the number 24
- 24 is even and can be split into prime factors: 2 × 2 × 2 × 3, or in Roman numerals II × II × II × III.
- XXIV has 4 letters. 784 of the numbers up to 1,000 have longer numerals.
- As a day of the month, XXIV is the 24th. Write a date
Counting from 21 to 30
Every number from 21 to 30 starts XX (20); only the ending changes.
| Number | Roman numeral |
|---|---|
| 21 | XXI |
| 22 | XXII |
| 23 | XXIII |
| 24 | XXIV |
| 25 | XXV |
| 26 | XXVI |
| 27 | XXVII |
| 28 | XXVIII |
| 29 | XXIX |
| 30 | XXX |