Roman Numeral Converter

Convert a Roman numeral to a decimal value or a decimal value to a Roman numeral.

Result:
1990
Roman=Decimal
M=1000
CM=900
XC=90
Total=1990

The Roman numeral converter allows you to convert numbers from 1 to 3,999,999 into Roman numerals.

Roman numerals are a system of numerical notation that originated in ancient Rome. Instead of using typical Arabic numerals (1, 2, 3), Roman numerals use a combination of letters to represent numbers. For example, "IV" represents the number 4, "X" represents 10, and "C" represents 100.

This tool allows you to convert numbers greater than 3,999. To input values such as M (1,000,000), simply append a dash to them, for example, M-. You can find more information about the equivalents of large numbers in the converter's table below.

How to use Roman Numerals Converter?

1. Select the method. Specify whether to convert Roman to Decimal or Decimal to Roman.
2. Enter the input (Roman numeral or decimal, depending on the selected method).
3. Click the "Convert" button.
4. Get the converted result.
5. See the full explanation in the table below the result.

Roman Numerals Table

Check the equivalent of a given Arabic number in Roman numerals. If you wish to learn Roman numerals, you can also print out this table.

Roman Numeral Decimal Number Calculator Input
I 1 I
IV 4 IV
V 5 V
IX 9 IX
X 10 X
XL 40 XL
L 50 L
XC 90 XC
C 100 C
CD 400 CD
D 500 D
CM 900 CM
M 1000 M
IV 4000 IV-
V 5000 V-
IX 9000 IX-
X 10000 X-
XL 40000 XL-
L 50000 L-
XC 90000 XC-
C 100000 C-
CD 400000 CD-
D 500000 D-
CM 900000 CM-
M 1000000 M-

Examples

Roman Numeral Decimal Number Calculator Input
XII 12 XII
XLV 45 XLV
CXXV 125 CXXV
CL 150 CL
MMXXX 2030 MMXXX
MMMCXXIII 3123 MMMCXXIII
XDXXI 10521 X-DXXI
DCXXIII 500123 D-CXXIII
MCM 1900000 M-CM-
MMD 2500000 M-M-D-