Roman Numerals Converter
Convert between Roman numerals and Arabic numbers with detailed explanations
Convert Roman Numerals
Enter any positive integer from 1 to 3999
Quick Examples
Basic Roman Numerals
I1
V5
X10
L50
C100
D500
M1,000
Common Combinations
IV4(V - I)
IX9(X - I)
XL40(L - X)
XC90(C - X)
CD400(D - C)
CM900(M - C)
Roman Numeral Rules
✓
Add when larger comes before smaller (VI = 6)
✓
Subtract when smaller comes before larger (IV = 4)
✓
Only I, X, and C can be subtracted
✓
Only one smaller numeral before larger
Understanding Roman Numerals
What are Roman Numerals?
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. They use combinations of letters from the Latin alphabet to signify values.
Key Principles
- •Addition: When a larger numeral comes before a smaller one, add their values (VI = 5 + 1 = 6)
- •Subtraction: When a smaller numeral comes before a larger one, subtract the smaller (IV = 5 - 1 = 4)
- •Repetition: A numeral can be repeated up to three times (III = 3, but not IIII for 4)
Conversion Examples
Example: 2024 → MMXXIV
2024 = 2000 + 20 + 4
2000 → MM (1000 + 1000)
20 → XX (10 + 10)
4 → IV (5 - 1)
Result: MMXXIV
Example: MCMXC → 1990
M = 1000
CM = 900 (1000 - 100)
XC = 90 (100 - 10)
Result: 1000 + 900 + 90 = 1990
Common Roman Numerals (1-100)
1
I
2
II
3
III
4
IV
5
V
6
VI
7
VII
8
VIII
9
IX
10
X
11
XI
12
XII
13
XIII
14
XIV
15
XV
16
XVI
17
XVII
18
XVIII
19
XIX
20
XX
21
XXI
22
XXII
23
XXIII
24
XXIV
25
XXV
26
XXVI
27
XXVII
28
XXVIII
29
XXIX
30
XXX
31
XXXI
32
XXXII
33
XXXIII
34
XXXIV
35
XXXV
36
XXXVI
37
XXXVII
38
XXXVIII
39
XXXIX
40
XL
41
XLI
42
XLII
43
XLIII
44
XLIV
45
XLV
46
XLVI
47
XLVII
48
XLVIII
49
XLIX
50
L
51
LI
52
LII
53
LIII
54
LIV
55
LV
56
LVI
57
LVII
58
LVIII
59
LIX
60
LX
61
LXI
62
LXII
63
LXIII
64
LXIV
65
LXV
66
LXVI
67
LXVII
68
LXVIII
69
LXIX
70
LXX
71
LXXI
72
LXXII
73
LXXIII
74
LXXIV
75
LXXV
76
LXXVI
77
LXXVII
78
LXXVIII
79
LXXIX
80
LXXX
81
LXXXI
82
LXXXII
83
LXXXIII
84
LXXXIV
85
LXXXV
86
LXXXVI
87
LXXXVII
88
LXXXVIII
89
LXXXIX
90
XC
91
XCI
92
XCII
93
XCIII
94
XCIV
95
XCV
96
XCVI
97
XCVII
98
XCVIII
99
XCIX
100
C