Type a number or a Roman numeral.
The tool auto-detects what you enter. Type 2024 to get MMXXIV, or type MMXXIV to get 2024.
Accepts Arabic numbers (1–3999) or standard Roman numerals (I, V, X, L, C, D, M).
Displays how a number is built from Roman numeral symbols, step by step.
Type, read, done.
No dropdowns, no buttons to press — the conversion happens as you type.
Type a number
Enter any Arabic number from 1 to 3999 — like 2024, 49, or 3999.
Or type a Roman numeral
Enter any valid Roman numeral — like MMXXIV, XLIX, or MMMCMXCIX — and the tool detects it automatically.
Read the result
The conversion appears instantly in the results panel, along with a badge showing which direction it converted.
Go deeper
Open Advanced options to see a step-by-step breakdown of how the Roman numeral is constructed, plus a full reference table.
Bidirectional, accurate, educational.
Every conversion follows standard Roman numeral rules — additive, subtractive, and the 1–3999 range.
Bidirectional conversion
Type either format and the tool detects it automatically. No toggles, no mode switching.
Step-by-step breakdown
See exactly how each Roman numeral is built from its symbols, with subtractive notation shown clearly.
Full reference chart
A complete table of key Roman numerals and their values, available at a glance in advanced mode.
Questions people actually ask.
The short answers — with the long ones one tap away.
How do I convert a number to a Roman numeral?+
Type the number into the input field and the tool automatically converts it to a Roman numeral. For example, 2024 becomes MMXXIV. The conversion uses standard subtractive notation rules.
How do I convert a Roman numeral back to a number?+
Just type the Roman numeral — like MMXXIV or XIV — into the same input field. The tool auto-detects that you've entered a Roman numeral and converts it to an Arabic number.
What is the largest number this converter supports?+
This tool supports standard Roman numerals from 1 to 3999 (MMMCMXCIX). Values above 3999 traditionally require a vinculum or overline notation, which is outside the scope of standard Roman numerals.
What are the basic Roman numeral symbols?+
The seven basic symbols are I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). All Roman numerals are built from these seven characters using additive and subtractive rules.
How does subtractive notation work in Roman numerals?+
When a smaller symbol appears before a larger one, it is subtracted. For example, IV = 4 (5 − 1), IX = 9 (10 − 1), XL = 40 (50 − 10), XC = 90 (100 − 10), CD = 400 (500 − 100), and CM = 900 (1000 − 100).
Is this Roman numeral converter free and does it work offline?+
It's completely free with no account or sign-up. All the conversion logic runs directly in your browser — no data is sent anywhere, and no external service is called.