Hexadecimal uses sixteen digits, 0–9 and A–F. Decimal 255 is FF, the largest value in one byte, which is why colour channels and byte values are written in hex.
How to use the Decimal to Hexadecimal Converter
- Number
- Input base
- Convert to
- Two’s complement width
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How it works
The number is read exactly using arbitrary-precision integers (so very long values are not rounded), then written in each base. Two’s complement shows how a negative number is stored in the chosen number of bits.
Formula
value = Σ digit × base^positionTo convert: divide repeatedly by the new base and read the remainders in reverse.Worked example
Inputs — Number: 255; Input base: Decimal (10); Convert to: Hexadecimal (16); Two’s complement width: No fixed width.
Results — Result = FF; Binary = 1111 1111; Octal = 377; Decimal = 255; Hexadecimal = FF; Bits needed = 8.
Key terms
- Bit
- A binary digit, 0 or 1.
- Nibble
- Four bits, one hexadecimal digit.
- Two’s complement
- The standard way computers store negative integers.
Frequently asked questions
What is 255 in binary?
1111 1111.
What is FF in decimal?
255.
How do I convert binary to hex by hand?
Split the bits into groups of four from the right and replace each group with its hex digit (0000 = 0 … 1111 = F).
What formula does the Decimal to Hexadecimal Converter use?
value = Σ digit × base^position.