Java program to convert celsius to fahrenheit

How to convert celsius to fahrenheit in java

This Java program is about the temperature conversion from Celsius to Fahrenheit.

The program asks the user to enter a temperature in celsius and displays the temperature in fahrenheit.

The formula to convert celsius into fahrenheit:

F = 32 + ( 9 * C / 5)     

Java program for temperature conversion. Celsius into fahrenheit:

import java.util.Scanner;

public class CelsiusIntoFahrenheit {

      public static void main(String[] args) {
           Scanner sc = new Scanner(System.in);
           double celsius, fahrenheit;
           System.out.print("Enter temperature in Celsius: ");
           celsius = sc.nextDouble();
           fahrenheit = 32 + (celsius * 9 / 5);
           System.out.println(celsius +" ºC is equal to " + fahrenheit + " ºF");                                  
     }
}

Formula to convert from Fahrenheit to Celsius:

C = (F - 32) * 5 / 9     

Java program to convert Fahrenheit into Celsius:

import java.util.Scanner;
public class FahrenheitIntoCelsius {
     public static void main(String[] args) {
           Scanner sc = new Scanner(System.in);
           double celsius, fahrenheit;
           System.out.print("Enter temperature in Fahrenheit: ");
           fahrenheit = sc.nextDouble();
           celsius = (fahrenheit - 32) * 5 / 9;
           System.out.println(fahrenheit +" ºF is equal to " + celsius + " ºC");                                            
     }
}

This is a very simple program but it’s usefull to demonstrate input with Scanner Class and output with System.out.println

Here is a temperature conversion table from -5 celsius to 5 celsius:

Celsius	Fahrenheit
-5	23
-4	24.8
-3	26.6
-2	28.4
-1	30.2
0	32
1	33.8
2	35.6
3	37.4
4	39.2
5	41

And finally, here is a Java program to obtain a conversion table similar to this one from -5 celsius to +5 celsius. There is no input. We use now a for loop with initial value -5.

public class TemperatureConversionTable {
     public static void main(String[] args) {
        double fahrenheit;
        for (int celsius = -5; celsius <= 5; celsius++) {
            fahrenheit = 32 + (celsius * 9 / 5);
            System.out.println(celsius + " ºC => " + fahrenheit + " ºF");                                          
        }
    }
}

Output:

-5 ºC => 23.0 ºF   
-4 ºC => 25.0 ºF
-3 ºC => 27.0 ºF
-2 ºC => 29.0 ºF
-1 ºC => 31.0 ºF
0 ºC => 32.0 ºF
1 ºC => 33.0 ºF
2 ºC => 35.0 ºF
3 ºC => 37.0 ºF
4 ºC => 39.0 ºF
5 ºC => 41.0 ºF