How to calculate percentages and discounts
Percentage calculations answer different questions. A percentage of a value, a percentage change and a discounted price use related but distinct formulas.
Calculate a percentageGet an instant result with your own values.Percentage formulas
To find x% of a number, multiply by x and divide by 100. For percentage change, divide the difference by the original value. For a discount, multiply the original price by (1 − rate ÷ 100).
Worked example
20% of 500 is 100. A 20% discount on 500 leaves a final price of 400. A second 10% discount applies to 400, not the original 500.
Percentage questions
Can successive discounts be added?
No. Each discount applies to the remaining price, so 20% then 10% equals a total reduction of 28%.
What is the percentage increase formula?
New value minus old value, divided by old value, multiplied by 100.