HOWTO · Java
How to Create a Temperature Converter in Java
This tutorial demonstrates how to create a temperature converter in Java.
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The temperature has three types of measuring units: Celsius, Fahrenheit, and Kelvin.
This tutorial demonstrates how to convert temperature from one unit to another for all types of measuring units.
Create a Temperature Converter in Java
According to the unit, there can be six types of conversions from one unit to another. Each conversion has a different formula.
The table below demonstrates all the formulas for temperature conversion:
| Conversion | Formula |
|---|---|
| Celcius to Fahrenheit | °F = (°C × 9/5) + 32 |
| Celcius to Kelvin | °K = °C + 273.15 |
| Fahrenheit to Celcius | °C = (°F − 32) × 5/9 |
| Fahrenheit to Kelvin | °K = (°F − 32) × 5/9 + 273.15 |
| Kelvin to Celcius | °C = °K − 273.15 |
| Kelvin to Fahrenheit | °F = (°K − 273.15) × 9/5 + 32 |
These six formulas can be implemented in Java to convert the temperature. We implemented all six formulas in one program to create a universal temperature converter.
See example:
package delftstack;
import java.util.*;
public class Temprature_Converter {
static Scanner sc = new Scanner(System.in); // Scanner Class
// Celcius to Fahrenheit
static double Celcius_to_Fahrenheit(double Celcius) {
double Fahrenheit = (Celcius * 9 / 5) + 32;
return Fahrenheit;
}
// Celcius to Kelvin
static double Celcius_to_Kelvin(double Celcius) {
double Kelvin = Celcius + 273.15;
return Kelvin;
}
// Fahrenheit to Celcius
static double Fahrenheit_to_Celcius(double Fahrenheit) {
double Celcius = (Fahrenheit - 32) * 5 / 9;
return Celcius;
}
// Fahrenheit to Kelvin
static double Fahrenheit_to_Kelvin(double Fahrenheit) {
double Kelvin = (Fahrenheit - 32) * 5 / 9 + 273.15;
return Kelvin;
}
// Kelvin to Celcius
static double Kelvin_to_Celcius(double Kelvin) {
double Celcius = Kelvin - 273.15;
return Celcius;
}
// Kelvin to Fahrenheit
static double Kelvin_to_Fahrenheit(double Kelvin) {
double Fahrenheit = (Kelvin - 273.15) * 9 / 5 + 32;
return Fahrenheit;
}
// Read the value of temperature given by the user
static double Input_Temperature(String Temperature) {
System.out.println("Enter the " + Temperature + " value:");
double val = sc.nextDouble();
return val;
}
// Print converted value of temperature
static void Output_Temperature(double Value, String Temperature) {
System.out.println("The " + Temperature + " value is: " + Value);
}
// Driver Method
public static void main(String args[]) {
System.out.println("Enter 1 for Celcius to Fahrenheit\nEnter 2 for Celcius to Kelvin\n"
+ "Enter 3 for Fahrenheit to Celcius\nEnter 4 for Fahrenheit to Kelvin\n"
+ "Enter 5 for Kelvin to Celcius\nEnter 6 for Kelvin to Fahrenheit\n7. Exit");
do {
System.out.println("\nEnter Your Temperature Choice Number: ");
int Temprature_Choice = sc.nextInt();
double Choice_Number = 0;
switch (Temprature_Choice) {
case 1:
Choice_Number = Input_Temperature("Celcius");
Output_Temperature(Celcius_to_Fahrenheit(Choice_Number), "Fahrenheit");
break;
case 2:
Choice_Number = Input_Temperature("Celcius");
Output_Temperature(Celcius_to_Kelvin(Choice_Number), "Kelvin");
break;
case 3:
Choice_Number = Input_Temperature("Fahrenheit");
Output_Temperature(Fahrenheit_to_Celcius(Choice_Number), "Celcius");
break;
case 4:
Choice_Number = Input_Temperature("Fahrenheit");
Output_Temperature(Fahrenheit_to_Kelvin(Choice_Number), "Kelvin");
break;
case 5:
Choice_Number = Input_Temperature("Kelvin");
Output_Temperature(Kelvin_to_Celcius(Choice_Number), "Celcius");
break;
case 6:
Choice_Number = Input_Temperature("Kelvin");
Output_Temperature(Kelvin_to_Fahrenheit(Choice_Number), "Fahrenheit");
break;
case 7:
System.exit(0);
break;
default:
System.out.println("Invalid Input");
}
} while (true);
}
}
The code above will take input from the user as a choice number and then the temperature to convert, then convert it based on the choice.
See output:
Enter 1 for Celcius to Fahrenheit
Enter 2 for Celcius to Kelvin
Enter 3 for Fahrenheit to Celcius
Enter 4 for Fahrenheit to Kelvin
Enter 5 for Kelvin to Celcius
Enter 6 for Kelvin to Fahrenheit
7. Exit
Enter Your Temperature Choice Number:
1
Enter the Celcius value:
50
The Fahrenheit value is: 122.0
Enter Your Temperature Choice Number:
2
Enter the Celcius value:
50
The Kelvin value is: 323.15
Enter Your Temperature Choice Number:
3
Enter the Fahrenheit value:
50
The Celcius value is: 10.0
Enter Your Temperature Choice Number:
4
Enter the Fahrenheit value:
50
The Kelvin value is: 283.15
Enter Your Temperature Choice Number:
5
Enter the Kelvin value:
50
The Celcius value is: -223.14999999999998
Enter Your Temperature Choice Number:
6
Enter the Kelvin value:
50
The Fahrenheit value is: -369.66999999999996
Enter Your Temperature Choice Number:
7
