# Roman Numerals and Alphabet Converter

## Using the Roman numerals and alphabet converter

The calculator will convert positive integer less than 5000 between Roman numerals and alphabet. The largest number you can enter is 4999, or MMMMCMXCIX in Roman numerals format.

Roman Numerals are based on seven symbols

• I = 1
• V = 5
• X = 10
• L = 50
• C = 100
• D = 500
• M = 1,000

There are several rules for writing Roman numerals.

• Repeating a numeral up to three times represents addition of the number. For example, XXX represents X + X + X = 30. Only I, X, C, and M can be repeated; V, L, and D cannot be repeated.
• Writing numerals that decrease from left to right represents addition of the numbers. For example, LX represents 50 + 10 = 60 and XVI represents 10 + 5 + 1 = 16.
• TWriting a smaller numeral to the left of a larger numeral represents subtraction. For example, IV represents 5 - 1 = 4 and IX represents 10 - 1 = 9. but the only pairs of numerals that use this subtraction rule are:
• IV = 5 - 1
• IX = 10 - 1
• XL = 50 - 10
• XC = 100 - 10
• CD = 500 - 100
• CM = 1000 - 10

Here is an example about repeating and subtraction rules:
Let's convert a Roman numerals to alphabet number.
MMCMXCIX
= M + M + (M - C) + (C - X) + (X - I)
= 1000 + 1000 + (1000 - 100) + (100 - 10) + (10 - 1)
= 2999

## Most used Roman numerals from one to a thousand

Roman Numerals Arabic
Numerals
uppercase lowercase
I i 1
II ii 2
III iii 3
IV iv 4
V v 5
VI vi 6
VII vii 7
VIII viii 8
IX ix 9
X x 10
XI xi 11
XII xii 12
XIII xiii 13
XIV xiv 14
XV xv 15
XVI xvi 16
XVII xvii 17
XVIII xviii 18
XIX xix 19
XX xx 20
XXI xxi 21
XXII xxii 22
XXIII xxiii 23
XXX xxx 30
XL xl 40
L l 50
LX lx 60
LXX lxx 70
LXXX lxxx 80
XC xc 90
C c 100
CC cc 200
CCC ccc 300
CD cd 400
D d 500
M m 1000