Roman Numeral Converter
Convert numbers to Roman numerals and back, from 1 to 3999, with validation that catches invalid forms like IIII or VX.
Runs on your device
Result
Results appear here as you type.
What it does
Type a number or a Roman numeral; the converter detects which one it is and checks that numerals follow standard subtractive notation.
How to use it
- Type 2026 or MMXXVI.
- Read the conversion.
- Copy the result.
Example
The example fills in realistic values and runs the tool. Select Try an example above to see it.
When it helps
- Tattoo and engraving dates.
- Clock faces and book chapters.
- Film copyright years.
Questions
Why stop at 3999?
Standard Roman numerals have no symbol for 5,000, so 3999 (MMMCMXCIX) is the largest regular number.
Is IIII accepted?
It appears on some clocks, but it is not standard, so the converter suggests IV.
More quick utilities tools
See all 15- Binary to Text Converter Convert text to 8-bit binary and binary back to readable text using UTF-8, so accented letters and emoji work in both directions.
- Fancy Text Generator Turn plain text into bold, italic, script, circled, monospace and upside down Unicode text you can paste into Instagram, X and TikTok bios.
- What Is My IP Address? See your public IP address instantly, check whether it is IPv4 or IPv6, and copy it with one click. No tracking, no logging.
- Random Number Generator Generate random numbers in any range, one or many at a time, with no repeats if you need them. Uses a cryptographically secure random source.
- Flip a Coin Flip a fair virtual coin once or up to 1,000 times and see heads and tails counts with percentages. Settle decisions instantly.
- Dice Roller Roll any number of dice with any number of sides, such as 2d6 or 1d20, with a modifier, individual results and the total.
People also use
Browse all 200 tools- Merge PDF Combine several PDF files into one document in the order you choose. Files are merged in your browser, so contracts and statements stay private. PDF
- Resistor Colour Code Calculator Decode 4-band and 5-band resistor colour codes into resistance and tolerance, or find the colour bands for a given resistance value. Electrical & engineering
- Tone Generator (Frequency Generator) Play a pure sine, square, triangle or sawtooth tone at any frequency from 20 Hz to 20 kHz to test speakers, headphones and hearing range. Device tests
- Diff Checker Compare two texts line by line and see exactly which lines were added or removed, with an option to ignore whitespace changes. Developer