Math and Number Tools
Binary, decimal, hex and octal converters and a Roman numeral converter. 8 tools, all running in your browser.
- Binary to Decimal Converter Convert binary numbers to decimal.
- Decimal to Binary Converter Convert decimal numbers to binary.
- Hex to Decimal Converter Convert hexadecimal numbers to decimal.
- Decimal to Hex Converter Convert decimal numbers to hexadecimal.
- Binary to Hex Converter Convert binary numbers to hexadecimal.
- Hex to Binary Converter Convert hexadecimal numbers to binary.
- Octal to Decimal Converter Convert octal numbers to decimal.
- Roman Numeral Converter Convert numbers to Roman numerals, and Roman numerals to numbers.
Number base conversions are exact, and very long numbers are handled without rounding. Binary and hex results are grouped in fours to make them easier to read.
Roman numerals follow the standard form and cover 1 to 3999.
Binary, octal, decimal and hexadecimal are the number bases used most in computing. Binary uses only 0 and 1 and is how computers store data, hexadecimal is a shorter way to write binary, and octal appears in Unix file permissions.
Every base conversion here is exact, even for very long numbers, because it uses whole-number arithmetic rather than rounding. Each page also shows the number in all four bases so you can compare them.
The Roman numeral converter works both ways for 1 to 3999 and rejects forms that are not standard, such as IIII, so you can use it to check homework or a year on a monument.