Number
490 in Roman numerals
490 is written CDXC
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 CDXC 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.
- XCtens · 9X before C means 100 − 10 = 90. This saves writing LXXXX.
400 + 90 = 490
The pairs CD and XC use 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 XD. It looks like a shortcut, but X may only come before L or C, not D. The correct form is CDXC.
- Not CCCCLXXXX (9 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today CDXC (4 letters) is the standard.
- There's no letter for zero. The zero is simply left out, which is why 490 has 2 parts, not 3.
About the number 490
- 490 is even and can be split into prime factors: 2 × 5 × 7 × 7, or in Roman numerals II × V × VII × VII.
- CDXC has 4 letters. 784 of the numbers up to 1,000 have longer numerals.
Counting from 481 to 490
Every number from 481 to 490 starts CD (400); only the ending changes.
| Number | Roman numeral |
|---|---|
| 481 | CDLXXXI |
| 482 | CDLXXXII |
| 483 | CDLXXXIII |
| 484 | CDLXXXIV |
| 485 | CDLXXXV |
| 486 | CDLXXXVI |
| 487 | CDLXXXVII |
| 488 | CDLXXXVIII |
| 489 | CDLXXXIX |
| 490 | CDXC |