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Numeral System Converter

Convert a value between Roman numerals, binary, octal, decimal, hexadecimal, base 36 and the ancient counting systems.

Convert between numeral systems

Result: —
Decimal value: —
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Roman numerals cover 1 to 3999 and ancient systems are shown for study. Everything is calculated locally in your browser.

How to use the Numeral System Converter

  1. Type the value you want to convert in the input box.
  2. Choose the system you are converting from and the system you want.
  3. Read the converted numeral, the decimal value and the steps taken.

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Frequently Asked Questions

Common questions about the free online numeral system converter.

Roman numerals, binary, octal, decimal, hexadecimal, base 36, plus the Mayan, Greek attic, Babylonian sexagesimal and Egyptian hieroglyphic systems.
Values from 0 to 3999 are accepted, because that is the range standard Roman numerals can write without extra notation.
The tool converts your input to a number and back again, so only genuine Roman forms such as MCMXCIV are accepted.
Digits are built from bars worth five, dots worth one and a shell glyph for zero, grouped in twenties from the bottom.
The tool uses the older acrophonic letters for one, five, ten, fifty, one hundred, five hundred and one thousand.
Numbers are split into powers of sixty. Tens are shown with the wedge sign and units with the small vertical sign.
Ancient systems had no single zero or place value in the modern sense, so the output is a faithful but simplified rendering.
No. Every conversion happens in your browser and the value you type is never uploaded or stored.
Yes. Press Copy result to place the conversion summary on your clipboard for notes or homework.

Last updated: October 10, 2026