Notation Conversion

Roman Numeral Converter

Convert numbers to Roman numerals or translate Roman numerals into Arabic integers instantly.

Convert Inputs

Arabic Number (1 - 3999)

Result Output

—

History & Rules

Understanding
Roman Numerals

Roman numerals are a system of numerical notation used by the ancient Romans. Numbers in this system are represented by combinations of letters from the Latin alphabet.

Roman Symbol	Decimal Value	Description
I	1	Unus
V	5	Quinque
X	10	Decem
L	50	Quinquaginta
C	100	Centum
D	500	Quingenti
M	1000	Mille

Fundamental Rules of Roman Numerals

Roman numerals rely on specific additive and subtractive rules:

Additive Rule: If a symbol is placed after a larger or equal symbol, its value is added. E.g., VIII = 5 + 1 + 1 + 1 = 8; XV = 10 + 5 = 15.
Subtractive Rule: If a smaller symbol is placed before a larger symbol, its value is subtracted. E.g., IV = 5 - 1 = 4; IX = 10 - 1 = 9; XC = 100 - 10 = 90.
Limits on Repetition: A symbol can be repeated at most three times consecutively. For example, IIII is not used; instead, write IV.

Typical Conversion Examples

Here are some common Roman numeral values for reference:

1994: MCMXCIV (M = 1000, CM = 900, XC = 90, IV = 4)
2024: MMXXIV (M + M = 2000, X + X = 20, IV = 4)
3999: MMMCMXCIX (The highest standard numeral without using overlines)

How the calculation works

Roman numerals add values, except when a smaller value is written before a larger one and is subtracted.

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

Subtract only powers of ten, and only from the next two higher symbols. 4 is IV, not IIII, in the modern form.

Worked example: 2026

2000 = MM.
20 = XX.
6 = VI.
2026 = MMXXVI.

Roman numerals

Number	Roman
4	IV
9	IX
2026	MMXXVI

Frequently asked questions

How is 2026 written in Roman numerals?▼

MMXXVI.

Why is 4 written IV?▼

I before V means 5 − 1.

What is the standard range of this converter?▼

The usual classical form covers 1 through 3,999.