Number Base Converter
This number base converter takes a number in binary, octal, decimal, hexadecimal or any base from 2 to 36 and shows it in all the common bases at once.
About this tool
This number base converter takes a number in binary, octal, decimal, hexadecimal or any base from 2 to 36 and shows it in all the common bases at once.
How to use it
- Enter the number.
- Choose the base it is written in, or pick Custom and enter a base from 2 to 36.
- Read the binary, octal, decimal and hex results, plus your custom target base.
- Click a result to copy it.
Good to know
- Bases above 10 use letters as digits: A = 10 up to Z = 35 in base 36.
- Hexadecimal (base 16) is common in programming because one hex digit represents exactly 4 bits.
- Octal (base 8) is used for Unix file permissions, such as 755.
- Very large integers above 9,007,199,254,740,991 (2^53 − 1) lose precision because JavaScript numbers are used.
Runs entirely in your browser — nothing you enter is uploaded or stored.
Frequently asked questions
How do I convert binary to decimal?
Multiply each digit by 2 raised to its position, counting from 0 on the right, and add them up. For example 1011 = 8 + 0 + 2 + 1 = 11.
Is hexadecimal case-sensitive?
No. A–F and a–f represent the same values.
Does it support fractions or negative numbers?
It converts whole numbers. Fractional parts are ignored.
Is anything sent to a server?
No. All conversions happen in your browser.