Roman Numeral Converter
Convert numbers to Roman numerals or decode Roman numerals back.
Roman Numeral Converter
Convert locally in your browser with standard Roman numeral validation.
Enter a whole number from 1 to 3999 for standard Roman numerals.
MMXXVI
Converted result
MMXXVI
Valid standard conversion.
Direction
Number to Roman numeral
Input value
2,026
Validation status
Valid
Standard range
1 to 3999
Symbol count
6
Breakdown
M + M + X + X + V + I
Local conversion
All conversion and validation runs instantly in your browser.
Standard notation
Invalid forms like IIII, VV, IC, IL, XM, VX, and MCMC are rejected.
Educational reference
Learn symbols, values, subtractive notation, and common use cases.
Dynamic Conversion Insights
How Roman Numerals Work
Letters, not digits
Roman numerals use letters instead of place-value digits.
Fixed values
Each symbol has a fixed value, such as X = 10 and C = 100.
Add or subtract
Values are added or subtracted depending on symbol order.
No zero
Standard Roman numerals do not include zero.
Roman Numeral Symbols and Values
I
1
V
5
X
10
L
50
C
100
D
500
M
1,000
Additive vs Subtractive Notation
Additive notation
Additive notation adds symbols from left to right. VI = 5 + 1 = 6. XII = 10 + 1 + 1 = 12.
Subtractive notation
A smaller value before a larger one is subtracted. IV = 4, IX = 9, XL = 40, and CM = 900.
Valid Roman Numeral Rules
Repeat limits
I, X, C, and M can repeat up to three times in a row.
No repeated V, L, D
V, L, and D should not repeat in standard Roman numerals.
Allowed subtractive pairs
Only IV, IX, XL, XC, CD, and CM are standard subtractive pairs.
Largest to smallest
Symbols generally move from largest to smallest unless using a valid subtractive pair.
Common Examples and Use Cases
Formula and Rule Explanation
Number to Roman
Subtract the largest Roman value possible, append the matching symbol, and repeat until the number reaches zero.
Roman to Number
Read symbols left to right. If a smaller value comes before a larger valid value, subtract it. Otherwise add it. This converter validates by converting the number back to Roman and comparing the standard form.
2026 = 1000 + 1000 + 10 + 10 + 5 + 1 = MMXXVI
IX = 10 − 1 = 9
Frequently Asked Questions
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