The number 255 in binary is 11111111. You can see this by looking at the table below. The top row shows the value of each bit, and the left column shows how many zeroes there are before the first 1. So, for example, 00011011 has three zeros before the first 1 (as do all numbers in this chart) and therefore has a decimal value of 3.
Why does that matter? Well, as I mentioned above, computers operate on binary logic and store data in “ones” and “zeros”. Every byte of computer memory is made up of eight bits — two four-bit chunks that together represent a single byte. So if you want to count up how many bytes of memory you have, you need to start by counting how many ones there are in a byte — and then multiply them by eight!
The decimal number corresponding to the binary number 11111111 is 65535. The binary number 11111111 has a decimal equivalent of 11111111.
Where does the decimal point go in the binary number?
The decimal point goes between the first and second digits of any number numeral, as in 5.5 or 29.8. This is true even for binary numbers, although there are no decimal points in them. Instead, you have to use the place value system to determine which digit is being used as the place holder for a decimal point. For example, when calculating a hexadecimal number such as F3A3C6D2, you would write it out as follows:
F3 A3 C6 D2 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
Each digit corresponds to four bits, so each digit represents two hexadecimal digits, so there are six digits total. So you would write out F3A3C6D2 this way:
1111 0010 1011 1001 1101 1110 1110 0100 1100 1101 0000 1010 1111 0010 0100 0000 0010 0000 0000 1011
Last modified: August 14, 2022