Roman Numeral Converter
Convert between Arabic numbers and Roman numerals (1–3999)
What is the Roman Numeral Converter?
The Roman numeral converter translates between standard numbers and Roman numerals in both directions. Type in 2024 and get MMXXIV. Type in XLVII and get 47. You need this for reading clock faces, interpreting copyright years in film credits, understanding chapter numbering in old books, or just satisfying curiosity. CalciHub's converter handles any number up to 3,999, the standard upper limit for traditional Roman numeral systems.
How Does It Work?
Roman numerals use seven letter symbols, each with a fixed value. Larger values generally come first. When a smaller value appears before a larger one, you subtract it, that's the subtractive principle. So IV is 4 (not 6), and IX is 9 (not 11). The converter applies these rules in both directions.
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000 Subtractive pairs: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900
• I = 1
• V = 5
• X = 10
• L = 50
• C = 100
• D = 500
• M = 1000
How to Use CalciHub's Roman Numeral Converter
1. Choose a direction: number to Roman numeral, or Roman numeral to number.
2. Type in your value.
3. Click Convert, the result appears immediately.
4. The tool also shows a breakdown of how the value was constructed.
Tip: Roman numerals have no symbol for zero and can't express fractions or negative numbers, if you see those in a context, it's a different system.
A Quick Example
Convert 1994 to Roman numerals. Break it down: 1000 = M, 900 = CM, 90 = XC, 4 = IV. Put it together: MCMXCIV. Going the other direction, enter MCMXCIV and the calculator reads M (1000) + CM (900) + XC (90) + IV (4) = 1994. This is actually one of the more complex Roman numerals you'll encounter because it uses subtractive notation three times.
1994 and 2024 (MMXXIV) look very different in Roman form, the shift from M+CM to MM reflects a clean thousand-year milestone.
Frequently Asked Questions
It's a stylistic tradition in watchmaking, not a Roman numeral rule. Using IIII creates visual symmetry opposite the VIII on the clock face, and some historians suggest it was preferred to avoid confusion with the Roman numeral for Jupiter (IV was an abbreviation of Iuppiter). Both forms are technically acceptable.
In the standard system, M is the largest symbol, and you can write up to three in a row (MMM = 3000). Adding 999 gives MMMCMXCIX = 3,999. Ancient Romans extended the system using bars over letters to multiply by 1,000, but that's rarely used today.
It means placing a smaller value before a larger one indicates subtraction. IV = 5 − 1 = 4. Without this rule, you'd need IIII for 4, which is technically allowed but nonstandard in modern usage.
Quite a bit. You'll see them on clock faces, in book chapter headings, in film copyright dates, in the names of monarchs and popes, at the Super Bowl, and in outlines and legal documents.
Yes, free to use in both directions. No limit on how many conversions you run.
Related Mathematics calculators
See all Mathematics →- Exponent CalculatorCalculate powers, roots, and exponential expressions.
- Circle CalculatorFind radius, diameter, circumference, and area of a circle.
- Distance CalculatorDistance between two points in 2D or 3D space.
- Concrete CalculatorCalculate concrete volume for slabs, columns, and footings.
- Binary CalculatorArithmetic and bitwise operations in binary, octal, decimal, or hex.
- Matrix CalculatorAdd, subtract, multiply matrices; find determinant and transpose.
More from Mathematics
View all posts →Longer reads from our mathematics collection.