Write a C program to enter any number from user and find the sum of all even numbers between 1 to n. How to find sum of even numbers in a given range using loop in C programming. Logic to find sum of even numbers in a given range in C program.

**Example**

**Input**

Input upper limit of even number: 10

**Output**

Sum of even numbers between 1 to 10: 30

## Required knowledge

Must read - Program to print even numbers in a given range

## Logic to find sum of even number

Below is the step by step descriptive logic to find sum of even numbers.

- Input upper limit to find sum of even number. Store it in some variable say N.
- Initialize another variable that will hold our sum with 0 say sum = 0.
- Initialize a loop from
`2`

to N and increment`2`

on each iteration. The loop structure should look like for(i=2; i<=N; i+=2). - Inside the loop body add the previous value of sum with i i.e. sum = sum + i.
- After the loop print the final value of sum.

## Program to find sum of even numbers

```
/**
* C program to print sum of all even numbers between 1 to n
*/
#include <stdio.h>
int main()
{
int i, n, sum=0;
/* Input upper limit from user */
printf("Enter upper limit: ");
scanf("%d", &n);
for(i=2; i<=n; i+=2)
{
/* Add current even number to sum */
sum += i;
}
printf("Sum of all even number between 1 to %d = %d", n, sum);
return 0;
}
```

**Note:** sum += i is similar to sum = sum + i. You can use any of them to find sum.

Output

Enter upper limit: 10 Sum of all even number between 1 to 10 = 30

## Program to find sum of even numbers in given range

```
/**
* C program to print sum of all even numbers in given range
*/
#include <stdio.h>
int main()
{
int i, start, end, sum=0;
/* Input lower and upper limit from user */
printf("Enter lower limit: ");
scanf("%d", &start);
printf("Enter upper limit: ");
scanf("%d", &end);
// If start is not even then make it even
if(start%2!=0)
{
start++;
}
for(i=start; i<=end; i+=2)
{
/* Add current even number to sum */
sum += i;
}
printf("Sum of all even number between %d to %d = %d", start, end, sum);
return 0;
}
```

Output

Enter lower limit: 6 Enter upper limit: 10 Sum of all even number between 6 to 10 = 24

Happy coding 😉

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