# 4 Percentage Calculators

Percentage calculators are used not only to solve math problems. They are very useful when you shop online as well.

## Why do we use percentage calculators online?

### What is X percent of Y?

For example, you are surfing the web and found the retail shop that gives 20% off on all shoes for today. You find nice shoes for \$75 and would like to find out how much they would cost with 20% discount applied. Use "What is X percent of Y" calculator to find out the discount.

### X is what percent of Y?

Percentage is a numerical expression indicating how one number compares to another. For example, lets say you know that 65,306 attended footy match between Collingwood Pies and Sydney Swans and you predict that 40,000 of these supporters were for Collingwood, so you can numerically express what portion of Collingwood fans were at MCG that day. Enter the numbers into "X (40,000) is what percent of Y (65,306)" and you get 61.25%.

### % decrease or increase

Money's real worth is lost over time and it's no secret money you have now is constantly losing value. What you could buy with \$5 about 25 years ago you will need about \$21 to buy now. Use our online percent increase/decrease calculator - fill in 5 in first box and 21 in second, the answer will shock you, it's 320%!

The same principles should be applied to other percentage calculators on this page.