Convert Between Number Systems
Type a number and choose its system: the same number appears at once in binary, octal, decimal and hexadecimal, plus any other base from 2 to 36 that you pick. Digits are grouped for easy reading — binary in fours, hex in pairs — and every value can be copied.
The conversion uses exact integer arithmetic, so even numbers with hundreds of digits are converted without rounding. Prefixes such as 0x, 0b and 0o, spaces and underscores are accepted. Everything runs in your browser.
Why Use This Number Base Converter?
- Binary, octal, decimal, hex and bases 2–36
- Numbers of any length, no rounding
- Accepts 0x, 0b and 0o prefixes, spaces and underscores
- Grouped digits and one-click copy
How to Convert a Number to Another Base
- Type the number you want to convert
- Choose its number system, for example "Decimal (10)"
- Read the number in the other systems and copy the one you need
Frequently Asked Questions
Is this converter free?
Yes, it is completely free and has no limits.
How do I convert binary to decimal by hand?
Multiply each digit by 2 raised to its position, counting from 0 on the right, and add the results. For example, 1011 = 1×8 + 0×4 + 1×2 + 1×1 = 11. Hexadecimal works the same way with powers of 16, where A–F stand for 10–15.
Can I convert negative numbers and fractions?
Negative integers are supported with a minus sign, for example −255 is −FF in hex. Fractions are not supported: the converter works with whole numbers, which is what binary and hex values usually are in programming.
Is any data sent to a server?
No. All conversions are calculated in your browser.