# Percentages » Percentages using ratio tables

To calculate from numbers to percentages and vice versa you can follow these steps:

 1 Make a ratio table with the amount at the top and the percentages at the bottom. 2 Write all the useful numbers that are given in the table. Underneath the total you always write 100%. 3 Find out what you need to do to get to your answer. Calculate using 1! 4 Calculate the percentage or the unknown number.

Below you can find two examples. In the first the percentage is calculated and in the second the amount is calculated.

Example 1
If you get a reduction of 369 euros on a washing machine of 1230 euros, what percentage is the reduction?

 : 1230 × 369 euros 1230 1 369 percentage 100 ... 30 : 1230 × 369

Calculation: 100 : 1230 × 369 = 30%

Example 2
How many cars are yellow when 12% of the 25 cars are yellow?

 :100 ×12 number of cars 25 ... 3 percentage 100 1 12 :100 ×12

Calculation: 25 : 100 × 8 = 3 yellow cars

Example 3
A tv costs 484 euros including 21% VAT. What is the cost of the tv excluding VAT?

 :121 ×100 euros 484 ... 400 percentage 121 1 100 :121 ×100

Calculation: 484 : 121 × 100 = 400 euros