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

## Required knowledge

Basic C programming, Relational operators, For loop

Learn more – Program to check odd numbers.

## 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.

- Input upper limit to find sum of odd numbers from user. Store it in some variable say
`N`. - Initialize other variable to store sum say
`sum = 0`

. - 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++)`

. - Inside the loop add
`sum`to the current value of`i`i.e.`sum = sum + i`

. - 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 ðŸ˜‰