Roman numeral converter

Calculate roman numeral converter with clear inputs and assumptions.

Your inputs stay in your browser. Displayed results are rounded to a maximum of 12 significant digits.

Method and assumptions

Method version 1.0.0 · Updated October 17, 2026

Calculate

Formula: Calculate roman numeral converter with clear inputs and assumptions.

Calculate roman numeral converter with clear inputs and assumptions.

value: Integer (1 to 3,999)

Results are estimates where noted and depend on the entered assumptions.

Calculate with code

These short examples use the same inputs and core calculation as this tool. Adapt validation and formatting to your application.

JavaScript

const value = 2026;
const symbols = [[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"]];
let n = value, out = ""; for (const [v, s] of symbols) while (n >= v) { out += s; n -= v; }
console.log(out); // MMXXVI

TypeScript

const value = 2026;
const symbols: [number, string][] = [[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"]];
let n = value, out = ""; for (const [v, s] of symbols) while (n >= v) { out += s; n -= v; }
console.log(out); // MMXXVI

Python

def roman(n):
    out = ""
    for value, symbol in [(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")]:
        while n >= value: out += symbol; n -= value
    return out
print(roman(2026))  # MMXXVI

Java

int n = 2026;
int[] values = {1000,900,500,400,100,90,50,40,10,9,5,4,1};
String[] symbols = {"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};
var out = new StringBuilder(); for (int i=0;i<values.length;i++) while(n>=values[i]) { out.append(symbols[i]); n-=values[i]; }
System.out.println(out); // MMXXVI

int n = 2026;
int[] values = [1000,900,500,400,100,90,50,40,10,9,5,4,1];
string[] symbols = ["M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"];
var output = new System.Text.StringBuilder(); for (int i=0;i<values.Length;i++) while(n>=values[i]) { output.Append(symbols[i]); n-=values[i]; }
Console.WriteLine(output); // MMXXVI