Roman Numbers Converter โ€“ Number to Roman Numeral Converter

Roman numbers converter - Convert numbers to Roman numerals and Roman numerals to numbers. Number to Roman numeral converter online. Supports numbers 1-3999 with step-by-step breakdown.

โ„น๏ธSupports numbers from 1 to 3,999. Valid Roman numerals use symbols I, V, X, L, C, D, M.

Result

Roman Numeral

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Results are estimates. Not professional advice.

Complete Guide to Roman Numerals

What Are Roman Numerals?

Roman numerals are a numeral system that originated in ancient Rome around 500 BCE. This system uses combinations of letters from the Latin alphabet to represent numbers. Unlike the Arabic numeral system (0-9) that we use today, Roman numerals don't include zero and use a different method of representing values.

Roman numerals remained the standard way of writing numbers throughout Europe well into the Late Middle Ages (around 1400 CE). Today, they're still used in many contexts including clock faces, book chapter headings, movie copyright dates, monarch names, and building cornerstones.

The Seven Basic Symbols

Roman numerals are built from seven fundamental symbols, each representing a specific value:

I
1
V
5
X
10
L
50
C
100
D
500
M
1,000

Core Rules for Reading and Writing Roman Numerals

Rule 1: Additive Principle

When a smaller symbol appears after a larger symbol, you add their values together.

Examples:

  • VI = V (5) + I (1) = 6
  • XII = X (10) + I (1) + I (1) = 12
  • LXX = L (50) + X (10) + X (10) = 70
  • MD = M (1000) + D (500) = 1,500

Rule 2: Subtractive Principle

When a smaller symbol appears before a larger symbol, you subtract the smaller value from the larger one. This rule only applies to specific pairs: IV, IX, XL, XC, CD, and CM.

Examples:

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

Rule 3: No More Than Three Repetitions

The same symbol cannot be repeated more than three times in a row. Use the subtractive principle instead.

Correct vs. Incorrect:

  • โœ“ IIII (4) is wrong โ†’ Use IV instead
  • โœ“ XXXX (40) is wrong โ†’ Use XL instead
  • โœ“ III (3) is correct - three is the maximum

Rule 4: Read from Left to Right

Always read Roman numerals from left to right, applying the additive or subtractive rules as you go.

Example: MCMXCIV (1994)

  • M = 1,000
  • CM = 1,000 - 100 = 900
  • XC = 100 - 10 = 90
  • IV = 5 - 1 = 4
  • Total: 1,000 + 900 + 90 + 4 = 1,994

How to Convert Numbers to Roman Numerals

Follow these steps to convert any number from 1 to 3,999 into Roman numerals:

  1. Step 1:Start with the largest Roman numeral value (M = 1,000) and work your way down.
  2. Step 2:For each value, determine how many times it fits into your number.
  3. Step 3:Write the corresponding Roman symbol(s) and subtract that value from your number.
  4. Step 4:Repeat with the next largest value until you reach zero.

Example: Converting 2,024 to Roman Numerals

2,024โ†’2,024 รท 1,000 = 2โ†’MM(remainder: 24)
24โ†’24 รท 10 = 2โ†’XX(remainder: 4)
4โ†’Use subtractive: 5 - 1โ†’IV

Result: MMXXIV = 2,024

How to Convert Roman Numerals to Numbers

To convert Roman numerals back to numbers, read from right to left and apply the rules:

Example: Converting XLII to a Number

Reading from right to left:

I = 1 (keep it, nothing smaller after)
I = 1 (add it, same or smaller after)
L = 50 (keep it, nothing smaller after)
X = 10 (subtract it, smaller before L)

Calculation: (50 - 10) + 1 + 1 = 42

Common Roman Numeral Values

NumberRoman Numeral
1-3I, II, III
4IV
5-8V, VI, VII, VIII
9IX
10, 20, 30X, XX, XXX
40, 50, 60XL, L, LX
90, 100XC, C
400, 500CD, D
900, 1,000CM, M
2,024MMXXIV
3,999MMMCMXCIX

Modern Uses of Roman Numerals

While Arabic numerals (0-9) are used for most calculations today, Roman numerals still appear in many places:

  • Clock faces: Many analog clocks use Roman numerals (I-XII) for the hours
  • Book chapters: Chapter numbers in books, especially in academic and classical literature
  • Movie copyrights: Copyright dates in film credits (e.g., "MMXXIV" for 2024)
  • Monarchs and popes: Sequential numbering (e.g., King Henry VIII, Pope John Paul II)
  • Building cornerstones: Construction dates on buildings and monuments
  • Sporting events: Super Bowl numbers (Super Bowl LVIII), Olympic Games (Games of the XXXII Olympiad)
  • Outlines: Numbering systems in documents and presentations

Tips for Using This Converter

  • โœ“Number to Roman: Enter any number from 1 to 3,999. The converter will show you the Roman numeral and a step-by-step breakdown.
  • โœ“Roman to Number: Type or paste Roman numerals (uppercase or lowercase). The converter automatically converts them to numbers.
  • โœ“Copy Results: Use the "Copy Result" button to quickly copy the converted value to your clipboard.
  • โœ“Breakdown Table: When converting numbers to Roman numerals, view the breakdown to understand how each symbol contributes to the total.

Whether you're working on a history project, reading classical literature, or simply curious about this ancient numbering system, our Roman numeral converter makes it easy to work with these timeless symbols. Practice converting numbers to improve your understanding, and use the breakdown feature to learn the conversion process step by step.

Frequently Asked Questions

How do you read Roman numerals?
You read them from left to right. Start with the largest values and add them together, taking note of the subtractive pairs (like IV or CM) where a smaller value precedes a larger one.
What is the largest Roman numeral?
In standard notation, the largest number that can be represented is 3,999 (MMMCMXCIX). For larger numbers, a horizontal bar called a vinculum is used over a letter to represent that it is multiplied by 1,000.
Is there a Roman numeral for zero?
No, the ancient Romans did not have a symbol for zero. They used the word "nulla" (the Latin word for 'none') when they needed to refer to zero.
Why can't you repeat a symbol more than three times?
This is a fundamental rule of Roman numerals. Instead of writing IIII for 4, you use the subtractive notation IV (5 - 1). This rule makes Roman numerals more compact and easier to read. The maximum repetition is three, which is why we have III (3) but IV (4), not IIII.
What are the subtractive pairs in Roman numerals?
There are six standard subtractive pairs: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). These pairs follow the rule where a smaller symbol placed before a larger one means subtraction. Only these specific combinations are valid in standard Roman numeral notation.
Can Roman numerals be written in lowercase?
While traditionally Roman numerals are written in uppercase (I, V, X, L, C, D, M), lowercase versions (i, v, x, l, c, d, m) are also valid and sometimes used in modern contexts. Our converter accepts both uppercase and lowercase input and will convert them correctly.
How do I convert large numbers beyond 3,999?
Standard Roman numerals only go up to 3,999 (MMMCMXCIX). For larger numbers, a vinculum (horizontal line) is placed over a numeral to multiply it by 1,000. For example, Vฬ… represents 5,000. However, this extended notation is rarely used in modern applications, and our converter focuses on the standard range of 1-3,999.