Roman Numeral Converter

Convert any whole number from 1 to 3,999,999 into Roman numerals, or convert a Roman numeral back into a number. A quick reference chart is included below. Everything runs in your browser.

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Number to Roman numeral

Enter a whole number from 1 to 3,999,999.

Roman numeral to number

Enter a Roman numeral such as MMXXVI.

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How Roman numerals work

Roman numerals are built from seven letters: I, V, X, L, C, D, and M, standing for 1, 5, 10, 50, 100, 500, and 1000. You add values by writing larger letters before smaller ones, so XVI is 10 + 5 + 1 = 16. To avoid four of the same letter in a row, a smaller value placed before a larger one is subtracted: IV is 5 minus 1 = 4, and IX is 10 minus 1 = 9. For numbers of 4,000 and above, a bar over a letter multiplies it by one thousand, so this converter places an overline above letters when needed.

Subtractive notation example Showing that IX equals ten minus one, which is nine. IX = X − I = 10 − 1 = 9 A smaller letter before a larger one is subtracted.
Subtractive notation keeps Roman numerals short, like IV for 4 and IX for 9.

Roman numeral reference chart

SymbolValue
I1
IV4
V5
IX9
X10
XL40
L50
XC90
C100
CD400
D500
CM900
M1000

Frequently asked questions

How do you write a number in Roman numerals?

Use the letters I, V, X, L, C, D, and M for 1, 5, 10, 50, 100, 500, and 1000. Place larger values before smaller ones to add, and a smaller value before a larger one to subtract, such as IV for 4 and IX for 9.

What are the seven Roman numeral symbols?

I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, and M = 1000. Every Roman numeral is a combination of these seven letters.

What is the largest number this converter supports?

It converts whole numbers from 1 to 3,999,999. Values of 4,000 and above use an overline above a letter to multiply it by one thousand, which this converter shows with a combining overline.

Why is there no symbol for zero?

The Roman numeral system has no symbol for zero. It was built for counting quantities of one or more, so the smallest value it can represent is one.

Is my data saved anywhere?

No. All conversions run entirely in your browser. Nothing you enter is uploaded or saved on a server.

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Disclaimer: Results are provided for general informational purposes only. Always double-check important figures independently.

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