# PHP: Calculate the ratio between two numbers.

This is a short guide on how to calculate the ratio between two numbers using PHP. This can be useful if you are presenting statistics, etc. Below, I’ve created a custom function that you can use.

## What is a ratio?

A ratio allows us to compare two numbers in a way that makes sense to the reader. Essentially, a ratio tells us how much one number contains the other number. Although coders typically stick to calculating percentages when it comes to these sort of things, there may come a use case where you have to display the ratio.

### Example.

150 people visit your website and 5 of those people agree to sign up for your newsletter. When you work out the math, that’s a ratio of 1:30. i.e. 1 in every 30 visitors signed up for your newsletter. As a percent, that’s 3.33%.

## Using PHP to calculate ratios.

Here’s the PHP function that you came for.

```/**
* Calculate the ratio between two numbers.
*
* @param int \$num1 The first number.
* @param int \$num2 The second number.
* @return string A string containing the ratio.
*/
function getRatio(\$num1, \$num2){
for(\$i = \$num2; \$i > 1; \$i--) {
if((\$num1 % \$i) == 0 && (\$num2 % \$i) == 0) {
\$num1 = \$num1 / \$i;
\$num2 = \$num2 / \$i;
}
}
return "\$num1:\$num2";
}

//Example returns 1:2
echo getRatio(2, 4), '<br>';

//Example returns 1:5
echo getRatio(2, 10), '<br>';```

In the code above, there are two examples showing you how this function works. Note that this function will return a string, with the resulting numbers being separated by a colon. Obviously, you can modify the return statement to meet your own needs. Or you could use PHP’s explode function to separate them.

I hope that you found this function as useful as I did!