/ algorithms

Convert Celsius to Fahrenheit

Let's take a look at the freeCodeCamp algorithm 'Convert Celsius to Fahrenheit'.

In this algorithm, we're passing an argument celsius into our convertToF() function. Within the function, we need to come up with the logic for the fahrenheit variable to correctly convert Celsius into Fahrenheit.

We know that in order to convert Celsius to Fahrenheit, we need to take the temperature in Celsius and multiply it by 9/5, then add 32.


  • convertToF(0) should return a number
  • convertToF(-30) should return a value of -22
  • convertToF(-10) should return a value of 14
  • convertToF(0) should return a value of 32
  • convertToF(20) should return a value of 68
  • convertToF(30) should return a value of 86


Let's take break down what we need to do in order to solve this algorithm. We need to take any given temperature in Celsius. Then we need to take that Celsius temperature and then divide it by 9/5. Afterwards, we take the product and then add 32. Lastly, we return the Fahrenheit value.

Here's a look at how we can pseudocode this:

// take temperature in celsius
    // multiply celsius by (9/5) and add 32
    // return fahrenheit

Breaking Down the Algorithm

Let's convert our psuedocode into actual code that the computer will understand.

Create the Function and Argument

First let's create the convertToF() function. Within that function, we will pass in the argument celsius.

function convertToF(celsius) {


Create the Logic

From here, we need to create the actual logic that will take the celsius input, then place it within our function.

var fahrenheit = celsius * (9/5) + 32;

Return The Result

Lastly, we just need to return the result which is stored in the fahrenheit variable.

return fahrenheit;


Here we can put all the pieces of the function together, then we can call it by passing in a value of 30 to test it out. If all goes well, our Celsius to Fahrenheit converter should return 86.

function convertToF(celsius) {
    var fahrenheit = celsius * (9/5) + 32;
    return fahrenheit;
// Call the function, passing an input of 30
// Expected output: 86

Hopefully this was a helpful walkthrough of how to convert celsius to fahrenheit!

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