C provides the short, long, and long long type specifiers to modify the width and range of integer types. These modifiers can be used with int and have implementation-defined sizes subject to the minimum requirements of the C standard.

#include <stdio.h>

int main()
{
    short int a = 100;
    int b = 1000;
    long int c = 100000L;
    long long int d = 1000000000LL;

    printf("short int      = %zu bytes\n", sizeof(a));
    printf("int            = %zu bytes\n", sizeof(b));
    printf("long int       = %zu bytes\n", sizeof(c));
    printf("long long int  = %zu bytes\n", sizeof(d));

    return 0;
}

Example Output #

The exact sizes depend on the implementation. A common result is:

short int      = 2 bytes
int            = 4 bytes
long int       = 8 bytes
long long int  = 8 bytes

Explanation #

The width modifiers used with integer types are:

short int
int
long int
long long int

The int keyword can be omitted when used with short, long, or long long:

short a;
long b;
long long c;

These are equivalent to:

short int a;
long int b;
long long int c;

Integer Width Modifier Table #

The standard guarantees ordering relationships between these types:

sizeof(short) <= sizeof(int) <= sizeof(long) <= sizeof(long long)

The actual sizes can be larger. For example, on a platform where long is 8 bytes, long and long long can have the same size.

The suffixes on the integer constants in the example specify their intended types:

sizeof reports the actual size of the type on the implementation, in bytes.