Humanizing byte size in C++

So, now i'm working with some C++ algorithms and need to show some info about memory usage, but the problem is, when you ask the sizeof(something) you'll get it in bytes which is kind of useless for a user to read when working.

I mean, i would be pissed if a program said it's using 33285996544 bytes of my memory.

So i made this small function to round it to some understandable size and return as a formated string, take a look:

#include <string>

string hByte(unsigned int bytes){
    string r;
    if (bytes <= 0) r = "0 Bytes";
    else if (bytes >= 1073741824) r = to_string(bytes/1073741824) + " GBytes";
    else if (bytes >= 1048576) r = to_string(bytes/1048576) + " MBytes";
    else if (bytes >= 1024) r = to_string(bytes/1024) + " KBytes";
    return r;
};

edited: changed to unsigned int in the argument.