C++ integer limits

Type Bits used Bytes used Min value Max value
Min formula
Max formula
char 8 1 -128 127 $$-(2^{7})$$ $$2^{7}-1$$
unsigned char 8 1 0 255 $$0$$ $$2^{8}-1$$
short int 16 2 -32768 32767 $$-(2^{15})$$ $$2^{15}-1$$
unsigned short int 16 2 0 65535 $$0$$ $$2^{16}-1$$
int 32 4 -2147483648 2147483647 $$-(2^{31})$$ $$2^{31}-1$$
unsigned int 32 4 0 4294967295 $$0$$ $$2^{32}-1$$
long long int 64 8 -9223372036854775808 9223372036854775807 $$-(2^{63})$$ $$2^{63}-1$$
unsigned long long int 64 8 0 18446744073709551615 $$0$$ $$2^{64}-1$$

The formulas are (where (n) is the number of bits):

min max
signed $$-(2^{n-1})$$ $$(2^{n-1})-1$$
unsigned $$0$$ $$2^n -1$$

We could use: http://en.cppreference.com/w/cpp/types/integer.