Number Base Converter
The Number Base Converter lets you convert values between common number systems, including binary, decimal, and hexadecimal, along with other supported bases. Quickly check number representations for programming, computer science, digital electronics, math exercises, and debugging. This free online base converter saves time when switching between numeral systems manually. Enter a number, choose the source and target bases, and convert your value in seconds.
FF
- Binary (2): 11111111
- Octal (8): 377
- Decimal (10): 255
- Hexadecimal (16): FF
Whole numbers only. Large values are converted exactly. You can use 0b, 0o and 0x prefixes, spaces or underscores in the input, and a leading minus sign.
What is Number Base Converter?
A Number Base Converter changes numeric values between supported number systems, such as binary, decimal, octal, and hexadecimal. Use this free online number base conversion tool for programming, mathematics, digital electronics, computer science exercises, and debugging when you need to represent the same value in different numeral systems.
Why use this tool?
- Convert between binary, octal, decimal, hexadecimal and any other base from 2 to 36.
- Every digit is checked, and the message names the first digit that is not valid in the base you chose.
- Very large numbers stay exact, because the conversion does not use floating-point arithmetic.
- The result is also shown in binary, octal, decimal and hexadecimal so you can compare them at a glance.
How to use Number Base Converter
- Step 1. Type the number you want to convert.
- Step 2. Choose the base it is written in under From base, and the base you want under To base.
- Step 3. Read the converted value. The list below it shows the same number in the four common bases.
Common use cases
Important notes
- Only whole numbers are supported. Fractions and decimal points are not converted.
- In bases above 10, letters stand for digits: A is 10, B is 11 and so on up to Z for 35. Input is not case-sensitive and results are shown in capitals.
- You can start a number with 0b, 0o or 0x when the From base is 2, 8 or 16, and use spaces or underscores to group digits.
- A leading minus sign is kept. The tool does not produce two's complement forms.
More Encoding & Conversion Tools
Number Base Converter FAQ
How do I convert binary to decimal?
Choose From base 2 and To base 10, then enter the binary number. For example, 1010 in binary is 10 in decimal.
How do I convert hexadecimal to decimal?
Choose From base 16 and To base 10. FF in hexadecimal is 255 in decimal.
Which digits are valid in each base?
A base uses the digits from 0 up to one less than the base, with letters for values of 10 and above. Binary allows 0 and 1, octal allows 0 to 7, and hexadecimal allows 0 to 9 and A to F.
Can it convert fractions or negative numbers?
Negative numbers keep their minus sign, but fractional values are not supported. Two's complement representations are not generated.
Does it handle very large numbers?
Yes. Large integers are converted exactly, without the rounding that affects ordinary floating-point numbers.