Roman Numeral Converter – Easily Change Numbers to Ancient Numerals

Ever wondered why movie sequels often use Roman numerals, like Rocky IV or Super Bowl LVII? Or maybe you’ve looked at the date carved on an old building and struggled to figure out what it meant. Roman numerals may be ancient, but they are still everywhere today. That’s where a Roman Numeral Converter comes in handy. With it, you can quickly change any number into Roman numerals, or take a Roman numeral and turn it back into a regular number you recognize.

Why Roman Numerals Still Matter

Even though we use Arabic numbers (1, 2, 3…) in everyday life, Roman numerals are far from obsolete. You’ll still find them:

• On clocks and watches with traditional faces.
  
• In book chapters, outlines, or film sequels.
  
• On certificates, monuments, and official documents.
  
• In sports, such as the Olympic Games or the Super Bowl.
  

Being able to read and convert them not only prevents confusion but also adds a touch of cultural knowledge and fun.

What You Enter in the Converter

The converter works in two directions:

• Number → Roman: Enter a whole number (1–3999) and get the Roman numeral version.
  
• Roman → Number: Enter a Roman numeral (I, V, X, L, C, D, M) and see its numeric value.
  

This range is important: the standard Roman numeral system only supports numbers from 1 to 3999 (after that, special overlines are needed, which most modern systems don’t use).

The Rules of Roman Numerals

Roman numerals use seven main letters:

• I = 1
  
• V = 5
  
• X = 10
  
• L = 50
  
• C = 100
  
• D = 500
  
• M = 1000
  

They follow some straightforward rules:

1. Additive rule: Write largest to smallest, then add. Example: VIII = 5 + 1 + 1 + 1 = 8.
   
2. Subtractive rule: A smaller number before a bigger one means subtraction. Example: IV = 4, IX = 9, CM = 900.
   
3. Repetition rule: I, X, C, and M can be repeated up to three times. But V, L, and D cannot repeat.
   

Formula Behind the Conversion

When turning a number into Roman numerals, the system checks the number against a descending value chart:

• 1000 → M
  
• 900 → CM
  
• 500 → D
  
• 400 → CD
  
• 100 → C
  
• 90 → XC
  
• 50 → L
  
• 40 → XL
  
• 10 → X
  
• 9 → IX
  
• 5 → V
  
• 4 → IV
  
• 1 → I
  

It subtracts and adds these values step by step until the whole number is converted.

Example: 1984 → MCMLXXXIV

• 1000 = M
  
• 900 = CM
  
• 50 = L
  
• 30 = XXX
  
• 4 = IV
  

How the Converter Works

Converting a number into Roman numerals

1. Enter a number between 1 and 3999.
   
2. The tool matches your number against the value table above.
   
3. It subtracts values and builds the numeral string.
   
4. Your result is shown instantly.
   

Converting Roman numerals back to numbers

1. Enter the Roman numeral letters.
   
2. The tool validates your input (no invalid combos like IC or VV).
   
3. It scans left to right, adding or subtracting values.
   
4. The total is displayed as a regular number.