Proportion calculator

The proportion calculator will help you solve proportion problems with ease and with the click of a button.

Guidelines to follow when using the proportion calculator

Each table has two boxes. The box on top is the numerator and the box at the bottom is the denominator. Therefore, each table represents a ratio.

Enter a ratio with two values in either table. Then enter only one value in the other table either on the box on top or the box at the bottom depending on the problem you are solving.

Hit the calculate button and the fourth value will be computed!

A couple of word problems showing how to use the proportion calculator

Solved Example #1

In a classroom, the ratio of boys to girls is 2/5. How many boys are there in this classroom if there are 20 girls? This means that if there are 2 boys in this class, then there are 5 girls.

Notice that the number of boys is on top and the number of girls is at the bottom.

Therefore, pick a table, either the one on the left or the one on the right, and put 2 in the box on top and put 5 in the box at the bottom.

Next, since 20 represents number of girls and this number was at the bottom in the ratio of boys to girls ( 2/5 ), it will go in the box at the bottom in the other table.

Hit calculate and you will see that there are 8 boys for 20 girls.



Solved Example #2

An employee working at Macy's, earns 120 dollars every 8 hours. How much will the employee earn in 25 hours? The ratio of number of hours worked to income is 8/120

Notice that the number of hours worked is on top and the income is at the bottom.

Therefore, pick a table, either the one on the left or the one on the right, and put 8 in the box on top and put 120 in the box at the bottom.

Next, since 25 represents the number of hours worked and this number was on top in the ratio of number of hours worked to income ( 8/120 ), it will also go in the box on top in the other table.

Hit calculate and you will see that your income is for 375 dollars when you work 25 hours.