Thread: need help with compound interest

Folks,
I've got this code below that creates an interest table with the interest compounded annually. I want to convert it to compound the interest on a monthly basis instead. Can anyone help and give advice as to what I need to focus on changing? Thanks!

Code:

/*Prints a table of compound interest */

#include <stdio.h>

#define NUM_RATES (sizeof(value) / sizeof(value[0]))
#define INITIAL_BALANCE 100.00

main()
{
	int i, low_rate, num_years, year;
	float value [5];

	printf("Enter interest rate: ");
	scanf("%d", &low_rate);
	printf("Enter number of years: ");
	scanf("%d", &num_years);

	printf("\nYears");
	for (i=0; i<NUM_RATES; i++)   {
		printf("%6d%%", low_rate+i);
		value[i] = INITIAL_BALANCE;
}
printf("\n");

for (year = 1; year <= num_years; year++)   {
	printf("%3d      ", year);
	for (i=0; i<NUM_RATES; i++)  {
		value[i] += (low_rate+i) / 100.00 * value[i];
		printf("%7.2f", value[i]);
	}
	printf("\n");
}
return 0;
}