# C program to find sum of odd numbers from 1 to n

Write a C program to find sum of all odd numbers from 1 to n using for loop. How to find sum of all odd numbers in a given range in C programming. Logic to find sum of odd numbers in a given range using loop in C programming.

Example

Input

`Input upper limit: 10`

Output

`Sum of odd numbers from 1-10: 25`

## Logic to find sum of odd numbers from 1 to n

Step by step descriptive logic to find sum of odd numbers between 1 to n.

1. Input upper limit to find sum of odd numbers from user. Store it in some variable say N.
2. Initialize other variable to store sum say `sum = 0`.
3. To find sum of odd numbers we must iterate through all odd numbers between 1 to n. Run a loop from 1 to N, increment 1 in each iteration. The loop structure must look similar to `for(i=1; i<=N; i++)`.
4. Inside the loop add sum to the current value of i i.e. `sum = sum + i`.
5. Print the final value of sum.

## Program to find sum of odd numbers from 1 to n

``````/**
* C program to print the sum of all odd numbers from 1 to n
*/

#include <stdio.h>

int main()
{
int i, n, sum=0;

/* Input range to find sum of odd numbers */
printf("Enter upper limit: ");
scanf("%d", &n);

/* Find the sum of all odd number */
for(i=1; i<=n; i+=2)
{
sum += i;
}

printf("Sum of odd numbers = %d", sum);

return 0;
}``````

Note: Do not confuse with the shorthand assignment operator `sum += i`. It is equivalent to `sum = sum + i`.

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

``````/**
* C program to print the sum of all odd numbers in given range
*/

#include <stdio.h>

int main()
{
int i, start, end, sum=0;

/* Input range to find sum of odd numbers */
printf("Enter lower limit: ");
scanf("%d", &start);
printf("Enter upper limit: ");
scanf("%d", &end);

/* If lower limit is even then make it odd */
if(start % 2 == 0)
{
start++;
}

/* Iterate from start to end and find sum */
for(i=start; i<=end; i+=2)
{
sum += i;
}

printf("Sum of odd numbers between %d to %d = %d", start, end, sum);

return 0;
}``````

Output

```Enter lower limit: 4
Enter upper limit: 11
Sum of odd numbers between 4 to 11 = 32```

Happy coding 😉 