Number
438 in Roman numerals
438 is written CDXXXVIII
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 CDXXXVIII is built
Roman numerals are written one decimal place at a time, largest first.
- CDhundreds · 4C before D means 500 − 100 = 400. This saves writing CCCC.
- XXXtens · 3X written 3 times: 3 × 10 = 30.
- VIIIones · 8V (5) plus III (3) makes 8.
400 + 30 + 8 = 438
The pair CD 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 CCCCXXXVIII (11 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today CDXXXVIII (9 letters) is the standard.
About the number 438
- 438 is even and can be split into prime factors: 2 × 3 × 73, or in Roman numerals II × III × LXXIII.
- CDXXXVIII has 9 letters. 31 of the numbers up to 1,000 have longer numerals.
Counting from 431 to 440
Every number from 431 to 440 starts CDX (410); only the ending changes.
| Number | Roman numeral |
|---|---|
| 431 | CDXXXI |
| 432 | CDXXXII |
| 433 | CDXXXIII |
| 434 | CDXXXIV |
| 435 | CDXXXV |
| 436 | CDXXXVI |
| 437 | CDXXXVII |
| 438 | CDXXXVIII |
| 439 | CDXXXIX |
| 440 | CDXL |