Roman Numeral Calculator
Convert between Roman numerals and standard numbers. Perform arithmetic with Roman numerals.
A Roman numeral converter translates between standard Arabic numbers and Roman numeral notation, supporting values from 1 to 3,999.
Examples
Year 2024
Parsing MCMXCIX
Frequently Asked Questions
Why is the limit 3,999?
Is there a Roman numeral for zero?
Quick Tips
- •Standard Roman numerals only go up to 3,999 (MMMCMXCIX).
- •A numeral can be repeated up to 3 times (III=3, XXX=30, CCC=300, MMM=3000).
- •Roman numerals have no zero — they were used for counting, not arithmetic.
- •Clock faces traditionally use IIII for 4 instead of IV.
A Roman numeral converter translates between standard Arabic numbers and Roman numeral notation, supporting values from 1 to 3,999.
How to Use This Calculator
Choose the conversion direction. To convert a number to Roman numerals, enter a number between 1 and 3,999. To convert Roman numerals to a number, type the Roman numeral string.
Understanding the Formula
Roman numerals use seven symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive notation: a smaller value before a larger one is subtracted (IV=4, IX=9, XL=40, XC=90, CD=400, CM=900).
Examples
Year 2024
2024 = MM (2000) + XX (20) + IV (4) = MMXXIV.
Parsing MCMXCIX
M=1000, CM=900, XC=90, IX=9. Total: 1000 + 900 + 90 + 9 = 1999.
Frequently Asked Questions
Why is the limit 3,999?
Standard Roman numerals use M (1000) as the largest symbol, and any symbol can repeat at most 3 times. So the maximum is MMMCMXCIX = 3,999. Extended notation with overlines (vinculum) can represent larger numbers.
Is there a Roman numeral for zero?
No. The Romans had no concept of zero as a number. The word "nulla" (meaning "nothing") was sometimes used as a placeholder, but there is no Roman numeral symbol for zero.
Assumptions & Limitations
- Only standard Roman numeral notation (I through M) is supported, limiting the range to 1-3,999.
- Subtractive notation is enforced as canonical form; non-standard representations like IIII are accepted as input but flagged.
- Extended vinculum notation for numbers above 3,999 is not supported.