How to convert roman numerals to decimal number.
Roman numerals to decimal number conversion
For roman numeral r:
- From the following table, find the highest roman numeral (n) with the highest decimal value (v)
that is taken from the left part of the roman numeral r:
| Roman numeral (n) |
Decimal value (v) |
| I |
1 |
| IV |
4 |
| V |
5 |
| IX |
9 |
| X |
10 |
| XL |
40 |
| L |
50 |
| XC |
90 |
| C |
100 |
| CD |
400 |
| D |
500 |
| CM |
900 |
| M |
1000 |
- Add to the decimal number x the value v of the roman numeral that you found:
x = x + v
Repeat stages 1 and 2 until you get all the roman numerals of r.
Example #1
r = XXXVI
| Iteration # |
Highest roman numeral (n) |
Highest decimal value (v) |
Decimal number (x) |
| 1 |
X |
10 |
10 |
| 2 |
X |
10 |
20 |
| 3 |
X |
10 |
30 |
| 4 |
V |
5 |
35 |
| 5 |
I |
1 |
36 |
Example #2
r = MMXII
| Iteration # |
Highest roman numeral (n) |
Highest decimal value (v) |
Decimal number (x) |
| 1 |
M |
1000 |
1000 |
| 2 |
M |
1000 |
2000 |
| 3 |
X |
10 |
2010 |
| 4 |
I |
1 |
2011 |
| 5 |
I |
1 |
2012 |
Example #3
r = MCMXCVI
| Iteration # |
Highest roman numeral (n) |
Highest decimal value (v) |
Decimal number (x) |
| 1 |
M |
1000 |
1000 |
| 2 |
CM |
900 |
1900 |
| 3 |
XC |
90 |
1990 |
| 4 |
V |
5 |
1995 |
| 5 |
I |
1 |
1996 |
How to convert number to roman numerals →
