Roman Numerals Converter: Rules, Chart and Examples

Roman numerals are a number system from ancient Rome that is still used today for style, tradition, and clarity. You see them on clock faces, in book chapters, at the end of film credits, on Super Bowl logos, and after the names of kings and popes. A Roman numerals converter turns ordinary numbers into this classic notation and back again in a moment.

The seven symbols

Every Roman numeral is built from just seven letters, each with a fixed value:

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

How the rules work

Two simple rules decide whether you add symbols together or subtract one from another.

• Additive rule: when a symbol is followed by one of equal or smaller value, you add them. VIII = 5 + 1 + 1 + 1 = 8.
• Subtractive rule: when a smaller symbol comes directly before a larger one, you subtract it. IV = 5 − 1 = 4 and IX = 10 − 1 = 9.
• The six subtractive pairs are IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, and CM = 900.
• There is no symbol for zero, and a symbol is normally not repeated more than three times in a row — which is exactly why 4 is IV rather than IIII.

Worked examples

Breaking a number into place values makes the notation easy to build.

Quick conversion chart

• 1 = I
• 4 = IV
• 5 = V
• 9 = IX
• 10 = X
• 40 = XL
• 50 = L
• 90 = XC
• 100 = C
• 500 = D
• 1000 = M

How to use the Roman numerals converter online

1. Type an ordinary number, for example 2024, to see it written in Roman numerals.
2. Or type Roman numerals, for example MMXXIV, to convert them back to a normal number.
3. Copy the result for your project, design, or tattoo idea.

Where you will still see them

• Clock and watch faces
• Book chapters, prefaces, and outlines
• Copyright dates and movie release years in credits
• Super Bowl and Olympic Games numbering
• Names of monarchs and popes, such as Henry VIII or Louis XIV

Handy tips

• Read from left to right, and only subtract when a smaller symbol sits directly before a larger one.
• If you ever find yourself writing four identical symbols in a row, switch to a subtractive pair instead.
• Standard Roman numerals only reach 3,999; larger numbers historically used a bar over a symbol to multiply it by 1,000.

FAQ

Q: How do you write 4 in Roman numerals?
A: Four is written IV, using the subtractive rule of one before five. The older form IIII sometimes appears on clock faces for visual balance, but IV is the standard.

Q: Why is there no zero in Roman numerals?
A: The system was designed for counting and recording quantities, not for place-value arithmetic, so it never needed a symbol for nothing. The concept of zero reached Europe much later through Arabic numerals.

Q: What is the largest standard Roman numeral?
A: Using only the basic symbols, the largest value is 3,999, written MMMCMXCIX. Beyond that you need bar notation to represent thousands.

Use the Roman Numerals Converter