Enter a whole number such as 2003, or a Roman numeral
such as MMIII, then click
Convert.
The input must be in the range of 1 - 4999, or I to MMMMCMXCIX.
The Basics
A smaller number in front of a larger
number means subtraction, all else means addition. For
example, IV means 4, VI means 6.
You would not put more than one smaller number in
front of a larger number to subtract. For example, IIV would not mean 3.
You must separate ones, tens, hundreds, and thousands
as separate items. That means that 99 is XCIX, 90 + 9, but never should be
written as IC. Similarly, 999
cannot be IM and 1999 cannot
be MIM.
I
The numeral one. II is two, III is three. You seldom see IIII as 4, since IV can also mean 4, plus its shorter
to write.
V
The numeral 5. IV is 4, VI is 6, VII is 7, VIII is 8.
X
The numeral 10. IX is 9, XI is 11, etc.
L
The numeral 50. XL would be 40.
C
The numeral 100. Think of Century
having a hundred years. C is
short for the Latin word Centum, but that's not very
easy to remember.
D
The numeral 500.
M
The numeral 1000.
Sometimes you will see a
numeral with a line over it. That means to multiply it
by 1000. A numeral V with a
line over it means 5000.
