Number
390 in Roman numerals
390 is written CCCXC
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 CCCXC is built
Roman numerals are written one decimal place at a time, largest first.
- CCChundreds · 3C written 3 times: 3 × 100 = 300.
- XCtens · 9X before C means 100 − 10 = 90. This saves writing LXXXX.
300 + 90 = 390
The pair XC 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 CCCLXXXX (8 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today CCCXC (5 letters) is the standard.
- There's no letter for zero. The zero is simply left out, which is why 390 has 2 parts, not 3.
About the number 390
- 390 is even and can be split into prime factors: 2 × 3 × 5 × 13, or in Roman numerals II × III × V × XIII.
- CCCXC has 5 letters. 604 of the numbers up to 1,000 have longer numerals.
Counting from 381 to 390
Every number from 381 to 390 starts CCC (300); only the ending changes.
| Number | Roman numeral |
|---|---|
| 381 | CCCLXXXI |
| 382 | CCCLXXXII |
| 383 | CCCLXXXIII |
| 384 | CCCLXXXIV |
| 385 | CCCLXXXV |
| 386 | CCCLXXXVI |
| 387 | CCCLXXXVII |
| 388 | CCCLXXXVIII |
| 389 | CCCLXXXIX |
| 390 | CCCXC |