10100101 binary to decimal

Binary to Decimal Converter

What is binary 10100101 in decimal?

Answer

Binary number 10100101 in decimal is

165

Read as an unsigned binary number — each place is worth a power of 2, 2⁰ on the right.

If this is an 8-bit signed number, the first bit is the sign: −37 in sign-magnitude, −90 in ones’ complement, −91 in two’s complement.

Digit × place value, then add

128 + 32 + 4 + 1 = 165

Binary number 10100101 in decimal is 165

Binary 10100101 in hexadecimal is A5 (0xA5): group the bits by four from the right — 1010 = A, 0101 = 5.

As an 8-bit signed number: −37 in sign-magnitude, −90 in ones’ complement, −91 in two’s complement. Unsigned it is 165.