Free tool

Roman Numerals Converter

Type a number or a Roman numeral below. The conversion runs as you type — no button to press.

becomes

becomes
Lowercase input accepted on both fields

How Roman numerals work

Roman numerals use seven letters — I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) — combined by addition and subtraction. A smaller symbol placed before a larger one is subtracted (IV = 4); placed after, it's added (VI = 6). This converter supports the standard range of 1 to 3999.

Frequently asked

What's the highest number I can convert?

3999 (MMMCMXCIX), using standard notation without overline extensions.

Does it accept lowercase Roman numerals?

Yes — type mmxxvi and it converts the same as MMXXVI.

Can I share a specific conversion?

Yes — a shareable link is generated automatically as you type, linking directly to that number's or numeral's own page.