Thread: Short program overflow issue?

There is a question in my text C Primer + that wants you to convert your age into seconds and it tells you that there are 3.156x(10 to the power of seven) seconds in a year. So I came up with the following program which produces the same output for every age. From that I a can see that I messed up. Can anyone see where I went wrong? My guess is that a long double isn't big enough to hold that no. of seconds.

Code:

/* convert age from years to seconds */
#include <stdio.h>
int main(void)
{
	int age;
	long double seconds_age;

	seconds_age = age * 3.156e7;
	printf("Enter your age: ");
	scanf("%d", &age);

	printf("%d years is %lf seconds", age, seconds_age);
}