How to determine how many bytes an integer needs?

Question

I\'m looking for the most efficient way to calculate the minimum number of bytes needed to store an integer without losing precision.

e.g.

int: 10 = 1 byte
         


        

Answer 1

You need to raise 256 to successive powers until the result is larger than your value.

For example: (Tested in C#)

long long limit = 1;
int byteCount;

for (byteCount = 1; byteCount < 8; byteCount++) {
    limit *= 256;
    if (limit > value)
        break;
}

If you only want byte sizes to be powers of two (If you don't want 65,537 to return 3), replace byteCount++ with byteCount *= 2.