How to convert Celsius to Fahrenheit in Java

The two temperature scales that are most commonly used are Fahrenheit and Celsius. Knowing how to convert Celsius to Fahrenheit is useful because it allows programmers to manage temperature calculations when creating weather-related apps.

Let’s first discuss the formula for converting Celsius to Fahrenheit.

Conversion formula

Using the formula below, we can change the temperature from Celsius to Fahrenheit:

F=(C×95)+32F = \left(C \times \frac{9}{5} \right) + 32

Here, FF is the Fahrenheit temperature, and CC is the Celsius temperature.

We need to apply the above formula to a provided temperature value to convert it from Celsius to Fahrenheit.

Example

Let’s suppose we have a temperature of 3030 degrees Celsius. Let’s put the value of CC in the formula above,

Given that C=30°CC = 30\degree C,

F=(C×95)+32=(30×95)+32=(30×1.8)+32=54+32=86°F\begin{split} F & = \left(C \times \frac{9}{5} \right) + 32 \\ & = \left(30 \times \frac{9}{5} \right) + 32 \\ & = (30 \times 1.8) + 32 \\ & = 54 + 32 \\ & = 86 \degree F \end{split}

Implementation

Now, let’s see an example of converting a temperature in Celsius to Fahrenheit in Java:

public class CelsiusToFahrenheit {
    public static void main(String[] args) {
        double c = 30;
        // Using the formula
        double f = (c * 9/5) + 32;
        System.out.println("After converting celsius to fahrenheit the value is " + f);
    }
}

Code explanation

  • Line 1: Define a public class named CelsiusToFahrenheit.

  • Line 2: Define the main method, which is the starting point of the Java program.

  • Line 3: Define a double variable c and declare and initialize it with the value 3030. This variable represents the temperature in Celsius.

  • Line 6: Calculate the temperature in Fahrenheit using the formula for converting Celsius to Fahrenheit. It multiplies the Celsius temperature (c) by 9/59/5 and adds 3232 to the result. The calculated Fahrenheit temperature is stored in the variable f.

  • Line 7: Print the result.

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