How number base conversion works
Every number base uses place values. Decimal uses powers of 10, binary uses powers of 2, octal uses powers of 8, and hexadecimal uses powers of 16. The written symbols change, but the quantity can remain the same.
For programming and computer science, binary and hexadecimal are especially common. Binary shows the exact bit pattern, while hexadecimal compresses each four-bit group into one readable symbol. Decimal is easier for humans to compare, so many workflows involve moving between all three.
When to use these converters
Use the focused converter pages when a single direction matters, such as hex to binary for byte groups or binary to decimal for a classroom place-value example. Use the combined number base converter when you want to enter one whole number and compare several bases at once. The ASCII table is useful when the value represents a character instead of only a numeric quantity.
These tools are intentionally limited to clear, small inputs. That makes them easier to use on mobile and avoids mixing unrelated rules for signed integers, floating point numbers, encodings, and overflow. If you are working inside a programming language, treat the result as the base value first and then apply the language-specific type rules separately.
Choose a conversion direction
Use Binary to Decimal when a base-2 value needs a familiar base-10 answer. Use Decimal to Binary for powers-of-two examples or programming notes. Use Binary to Hex and Hex to Binary when you are comparing bit groups, bytes, or hexadecimal notation. If you want several results at once, open the Number Base Converter.
Binary numbers are not always text
A binary value can represent a number or character data depending on context. For example, the text character 0 is 00110000 in ASCII, while the numeric value zero is simply 0 in binary. Use the Binary Code Translator when the input is meant to be readable text, and use these number-base pages when the input is a numeric quantity.
Common base conversion examples
Binary 1010 equals decimal 10 and hexadecimal A. Decimal 42 equals binary 101010 and hexadecimal 2A. Hexadecimal FF equals decimal 255 and binary 11111111. These examples show why padding can matter: 1010 is the same quantity as 00001010, but the padded form is easier to compare as one byte.
When reading a byte, keep the distinction between the value and its display format. A byte can be shown as eight binary bits, two hexadecimal digits, or one decimal number. None of those formats changes the underlying quantity. The correct choice depends on whether you are teaching place values, checking a program value, inspecting a protocol field, or reading a character encoding.