At One Place

900 in Roman numerals

900 in Roman numerals
CM

900 is written CM in Roman numerals. That is 1 symbol group added together, reading left to right from the largest value down.

How it breaks down

CM = 900 = 900
Group Value Subtraction Running total
CM 900 M − C 900

Why the smaller symbol comes first

CM uses subtractive notation in one place: CM means M minus C, or 900. A smaller symbol placed before a larger one is subtracted from it rather than added, which is why IX is nine and not eleven.

Only six such pairs are valid — IV, IX, XL, XC, CD and CM. That restriction is what makes the notation unambiguous: IIII and IC both look like they should work, but neither is standard, and only one spelling of any number is correct.

The symbols

Symbol Value Used here
I 1 no
V 5 no
X 10 no
L 50 no
C 100 yes — 1×
D 500 no
M 1,000 yes — 1×

The same number, other ways

In words
Nine hundred
Roman numeral
CM
Symbol count
2 characters
Binary
1110000100
Hexadecimal
384

The numbers either side

Number Roman numeral
898 DCCCXCVIII
899 DCCCXCIX
900 CM ←
901 CMI
902 CMII

Common questions

What is 900 in Roman numerals?
900 is CM.
What does CM mean?
CM is the Roman numeral for 900 — 900.
How do you write 900 in Roman numerals?
Take the largest value that fits and repeat until nothing is left: CM (900). That gives CM.

Related pages

Sources

  1. Calculated on this page — At One Place

How these figures are compiled and checked