Roman Numeral Converter

Convert between Arabic numbers and Roman numerals instantly. Get detailed breakdowns, place value analysis, and visual charts.

Converter

1-3999

Enter a number between 1 and 3999

Enter a number or Roman numeral, then click Convert to see the result with detailed breakdown, charts, and analysis.

Complete User Guide

What Are Roman Numerals?

Roman numerals are a numeral system originating in ancient Rome. They use combinations of letters from the Latin alphabet — I, V, X, L, C, D, and M — to represent values. Unlike our modern decimal system, Roman numerals do not use place value in the same way and have no symbol for zero.

Basic Roman Numeral Symbols

Symbol Value Origin
I1One finger
V5Hand (5 fingers)
X10Two hands crossed
L50From symbol ↆ
C100Centum (Latin for 100)
D500Half of Φ (1000)
M1000Mille (Latin for 1000)

Rules for Roman Numerals

Additive Rule

When a smaller or equal symbol follows a larger one, add the values. Example: VI = 5 + 1 = 6

Subtractive Rule

When a smaller symbol precedes a larger one, subtract the smaller. Example: IV = 5 - 1 = 4. Only I, X, and C can be subtracted.

Repetition Rule

I, X, C, and M can be repeated up to 3 times consecutively. V, L, and D are never repeated. Example: III = 3, but IIII is invalid.

Subtractive Combinations

CombinationValueMeaning
IV45 - 1
IX910 - 1
XL4050 - 10
XC90100 - 10
CD400500 - 100
CM9001000 - 100

How to Use This Converter

  1. Choose your conversion direction (Number → Roman or Roman → Number)
  2. Enter your value in the input field or use a quick-select button
  3. Click 'Convert' to see the result
  4. Review the step-by-step breakdown and place value analysis
  5. Explore the charts for visual representation

Important Notes

  • Standard Roman numerals represent values from 1 to 3,999.
  • Roman numerals have no symbol for zero — the concept didn't exist in ancient Rome.
  • Roman numerals are still used today for clock faces, book chapters, movie sequels, and more.

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