Temperature Converter Console App in C Sharp

Here’s a complete Temperature Converter Console App in C#, along with a detailed explanation of how the code works.

This app allows users to convert between Celsius, Fahrenheit, and Kelvin.

Features

• Convert:
  • Celsius to Fahrenheit/Kelvin
  • Fahrenheit to Celsius/Kelvin
  • Kelvin to Celsius/Fahrenheit
• Input validation
• User-friendly menu
• Repeats until the user chooses to exit

Full Code

using System;

class TemperatureConverterApp
{
    static void Main()
    {
        Console.WriteLine("Welcome to the Temperature Converter!");

        bool exit = false;

        while (!exit)
        {
            Console.WriteLine("\nSelect an option:");
            Console.WriteLine("1. Celsius to Fahrenheit");
            Console.WriteLine("2. Celsius to Kelvin");
            Console.WriteLine("3. Fahrenheit to Celsius");
            Console.WriteLine("4. Fahrenheit to Kelvin");
            Console.WriteLine("5. Kelvin to Celsius");
            Console.WriteLine("6. Kelvin to Fahrenheit");
            Console.WriteLine("7. Exit");
            Console.Write("Your choice: ");

            string input = Console.ReadLine();

            if (!int.TryParse(input, out int choice) || choice < 1 || choice > 7)
            {
                Console.WriteLine("Invalid choice. Please enter a number from 1 to 7.");
                continue;
            }

            if (choice == 7)
            {
                exit = true;
                Console.WriteLine("Goodbye!");
                break;
            }

            Console.Write("Enter the temperature value: ");
            string tempInput = Console.ReadLine();

            if (!double.TryParse(tempInput, out double temperature))
            {
                Console.WriteLine("Invalid temperature value. Please enter a numeric value.");
                continue;
            }

            double result = 0.0;
            string resultUnit = "";

            switch (choice)
            {
                case 1:
                    result = CelsiusToFahrenheit(temperature);
                    resultUnit = "Fahrenheit";
                    break;
                case 2:
                    result = CelsiusToKelvin(temperature);
                    resultUnit = "Kelvin";
                    break;
                case 3:
                    result = FahrenheitToCelsius(temperature);
                    resultUnit = "Celsius";
                    break;
                case 4:
                    result = FahrenheitToKelvin(temperature);
                    resultUnit = "Kelvin";
                    break;
                case 5:
                    result = KelvinToCelsius(temperature);
                    resultUnit = "Celsius";
                    break;
                case 6:
                    result = KelvinToFahrenheit(temperature);
                    resultUnit = "Fahrenheit";
                    break;
            }

            Console.WriteLine($"Result: {result:F2} {resultUnit}");
        }
    }

    // Conversion Methods
    static double CelsiusToFahrenheit(double c) => (c * 9 / 5) + 32;
    static double CelsiusToKelvin(double c) => c + 273.15;
    static double FahrenheitToCelsius(double f) => (f - 32) * 5 / 9;
    static double FahrenheitToKelvin(double f) => (f - 32) * 5 / 9 + 273.15;
    static double KelvinToCelsius(double k) => k - 273.15;
    static double KelvinToFahrenheit(double k) => (k - 273.15) * 9 / 5 + 32;
}

Code Breakdown

using System;

Imports the System namespace to use Console and basic input/output features.

Main() Method

This is the entry point of the program where execution begins.

bool exit = false;

Initializes a loop control variable. The loop will keep running until the user chooses to exit.

User Menu

Displays a menu of options for the user to choose the type of conversion:

Console.WriteLine("1. Celsius to Fahrenheit");
...
Console.WriteLine("7. Exit");

The program reads and validates the user’s choice:

string input = Console.ReadLine();
int.TryParse(input, out int choice)

Reading Temperature Input

After selecting a conversion type, the user is prompted to enter a temperature value:

Console.Write("Enter the temperature value: ");

Input is parsed and validated using double.TryParse.

Switch Statement

Depending on the user’s selection, the correct method is called:

switch (choice)
{
    case 1:
        result = CelsiusToFahrenheit(temperature);
        resultUnit = "Fahrenheit";
        break;
    ...
}

Conversion Methods

Defined at the bottom of the class, each method performs a standard conversion:

static double CelsiusToFahrenheit(double c) => (c * 9 / 5) + 32;

• All formulas follow well-known conversion equations:
  • °F = (°C × 9/5) + 32
  • °C = (°F − 32) × 5/9
  • K = °C + 273.15

Displaying Results

After the conversion, the result is printed with two decimal places:

Console.WriteLine($"Result: {result:F2} {resultUnit}");

Example Output

Welcome to the Temperature Converter!

Select an option:
1. Celsius to Fahrenheit
...
7. Exit
Your choice: 1
Enter the temperature value: 100
Result: 212.00 Fahrenheit

How to Run This Program

1. Open Visual Studio or another C# IDE.
2. Create a new Console App project.
3. Replace the contents of Program.cs with the code above.
4. Run the application.