# C Program To Convert Decimal To Octal

In this post, we will learn how to convert decimal to octal using C Programming language.

This program takes a decimal number as an input and converts it into an octal number using a user defined function.

So, without further ado, let’s begin this tutorial.

Contents

## C Program To Convert Decimal To Octal

```// C Program To Convert Decimal To Octal
#include <stdio.h>
#include <math.h>

int decimaltoOctal(int num){
int octal = 0, temp = 1;

while (num != 0){
octal = octal + (num % 8) * temp;
num = num / 8;
temp = temp * 10;
}
return octal;
}

int main(){
int num;

printf("Enter a decimal number: ");
scanf("%d", &num);

printf("Equivalent Octal Number is: %d", decimaltoOctal(num));
return 0;
}
```

Output

``````Enter a decimal number: 568
Equivalent Octal Number is: 1070
``````

## How Does This Program Work ?

``````    int num;
``````

In this program, we have declared an int data type variable named as num.

``````    // Asking for Input
printf("Enter a decimal number: ");
scanf("%d", &num);
``````

Then, the user is asked to enter a number. The value of this number will get stored in the num named variable.

``````    printf("Equivalent Octal Number is: %d", decimaltoOctal(num));
``````

Now, we call the custom function named decimaltoOctal which returns the octal number.

``````int decimaltoOctal(int num){
int octal = 0, temp = 1;

while (num != 0){
octal = octal + (num % 8) * temp;
num = num / 8;
temp = temp * 10;
}
return octal;
}
``````

We have defined a custom function named decimaltoOctal which converts and returns decimal numbers into octal numbers.

## Conclusion

I hope after going through this post, you understand how to convert decimal to octal using C Programming language.

If you have any doubt regarding the program, feel free to contact us in the comment section. We will be delighted to help you.