Free Roman Numeral Converter
Convert integers to Roman numerals and vice versa. Fast, accurate, and runs entirely in your browser.
The Roman Numeral Converter turns integers into Roman numerals and back. It runs entirely in your browser and is accurate across the standard range.
About Roman Numeral Converter
A Roman numeral converter translates between modern integers and the symbols of the ancient Roman system, using I, V, X, L, C, D, and M to represent values from one to several thousand. It is handy for historical references, clock faces, movie prequels, academic work, and formal document numbering where a number should read as letters rather than digits. The conversion follows the traditional subtractive notation rules, such as IV for four and IX for nine, so the output is accurate and standardized for every supported value instead of an improvised or non-standard form.
The notation has two core rules: a symbol is added when the values run in descending order, as in XVI for sixteen, and a smaller value placed before a larger one is subtracted, as in IV and IX. This converter handles integers from one to 3999 with a greedy algorithm that repeatedly subtracts the largest possible Roman value and appends its symbol, while the reverse direction parses the numeral right to left, adding or subtracting each symbol according to its relationship with the one before it. Out-of-range or malformed input is rejected rather than guessed, so you always get a trustworthy answer or a clear signal that the value is unsupported.
You can convert in both directions with the same tool: type an integer in the one to 3999 range to see its Roman numeral, or enter a valid Roman numeral to read back the corresponding number. The conversion happens instantly in the browser without sending any data over the network, and the result is a single clickable field that copies to your clipboard for use in a document, slide, or code. That makes it a quick reference for classrooms, a fast check when restoring old machinery or reading an inscription, and a clean way to handle ordinal numbering without a calculator.
How to use this Roman Numeral Converter
- Enter an integer (1–3999) in the left field to see the Roman numeral.
- Enter a Roman numeral in the right field to convert it back to an integer.
- Verify the result displays correctly below the input fields.
- Click the result box to copy the value to your clipboard.
FAQ
What is a Roman numeral converter?
A Roman numeral converter changes between modern integers (like 2024) and Roman numerals (like MMXXIV), using the traditional symbols I, V, X, L, C, D, and M.
Are the numbers I convert uploaded or stored?
No. All conversions happen locally in your browser using JavaScript. Nothing is uploaded or stored.
Is this tool free?
Yes, completely free with no usage limits.
What is the range?
This converter supports integers from 1 to 3999, which covers the standard Roman numeral system without extended notation.