Calculators
Number Base Converter: Binary, Decimal, Hex and Octal
Free, no sign-up, works in your browser. Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36. Type in any box and the others update instantly, exactly, for numbers of any size.
Type in any box; the others update. Whole numbers of any size, including negatives.
8 bits needed
Converted exactly on your device, with no rounding for large numbers.
How to use the Number Base Converter
- Type a number in the box for its base, such as binary or hex.
- Read the same number in every other base.
- Copy the one you need, with or without a 0x or 0b prefix.
Frequently asked questions
- How do I convert binary to decimal?
- Each binary digit is worth twice the one to its right: 1, 2, 4, 8 and so on. Add up the values where there's a 1. 1011 is 8 + 2 + 1 = 11.
- How do I convert decimal to hexadecimal?
- Divide by 16 repeatedly and write down the remainders from last to first, using A-F for 10-15. 255 becomes FF. This tool does it as you type.
- Are negative numbers supported?
- Yes. They're shown with a minus sign, and as a two's complement bit pattern at the smallest standard width.
- Is there a size limit?
- No practical one: very large numbers are converted exactly, without rounding.
- Is the Number Base Converter free?
- Yes. It's free to use, with no sign-up and nothing to install.
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