Decimal to Binary Converter
Convert decimal numbers to binary, hex, and octal instantly. Exact big-integer math, works with negative and very large numbers.
Independently verified for accuracy
Calculator by Toolsloft ↗- Binary
- 11111111
- Hexadecimal
- ff
- Octal
- 377
Turn any decimal number into binary, and see its hexadecimal and octal forms alongside it. Type a whole number, positive or negative, and the converter reads it exactly, even when the value is far larger than a normal calculator can hold. It is handy for reading register values, bit masks, and homework the moment you need the answer.
How this is calculated
The number is parsed as a base-10 integer using big-integer arithmetic, then rewritten in base 2, base 16, and base 8 by repeated division with remainders, which is the standard positional-notation method. Nothing is rounded, so the binary output is an exact representation of the input. Negative numbers are shown in sign-magnitude form with a leading minus sign.
How to use
- Type the decimal number you want to convert.
- Read the binary result, plus its hexadecimal and octal forms.
- Copy whichever representation you need.
Examples
- Byte value:
255 becomes 11111111 in binary - Negative:
-6 becomes -110 in binary
FAQ
- How are negative numbers shown?
- In sign-magnitude form: the magnitude is converted to binary and a minus sign is added in front. This tool does not use fixed-width twos complement, since that needs a chosen bit width.
- Can it handle very large numbers?
- Yes. Conversion uses big-integer math, so numbers with hundreds of digits convert exactly without overflow or rounding.