Discount calculator
Final price after a discount and exactly how much you save.
Calculator inputs
Results
Enter your values and press “Calculate” to see the result.
In short
- What it calculates
- Final price after a discount and exactly how much you save.
- Formula used
Saving = price × discount ÷ 100- Example
- £89.90 with 30% off:
Discount calculator
Working out 37% off in your head at the till is awkward. Enter the price and the percentage and see immediately what you will pay.
The result includes the saving so you can judge whether it is worth it.
How it works
The discount is computed on the original price and subtracted. The percentage you end up paying is simply one hundred minus the discount.
Formula
Saving = price × discount ÷ 100
Final price = price − saving
Final price = price × (1 − discount/100)
Worked example
£89.90 with 30% off:
Saving: £26.97
Final price: £62.93
You pay 70% of the original price
Explanation
The crossed-out price has to be real
Under the European directive known as Omnibus, a shop announcing a reduction must state the lowest price applied in the previous thirty days, not an invented reference price. It exists precisely to stop the practice of raising a price days before Black Friday and then striking it through.
Recovering the original price
If you know the final price and the percentage applied, you do not get back to the starting price by adding that same percentage. An item costing 100 with 20% off becomes 80; adding 20% to 80 gives 96, not 100. You have to divide by 0.8. It is the same reasoning as with tax.
Percentage points and percentages
Going from a 20% discount to a 25% one is a five percentage point increase, but a 25% increase in relative terms. Leaflets often exploit the ambiguity, so it pays to know which of the two figures is being advertised.
Discount on top of discount
Applying 30% and then a further 20% is not the same as 50%: the second is calculated on what remains, and the real result is 44%. The more discounts you chain, the further you get from the simple sum.
Frequently asked questions
How do I apply two discounts in a row?
Work out the first, take the result and apply the second to it. Never add the percentages: 20% + 20% equals 36%, not 40%.
Is the discount applied before or after tax?
It depends on the retailer, but consumer prices usually include tax already, so the discount applies to the total.
How do I find the price before the discount?
Divide the sale price by one minus the discount as a decimal. At 20%, divide by 0.8; adding 20% to the sale price gives a different answer.
What does a 3-for-2 offer work out at?
It amounts to 33.33% off the group: you pay for three and take four, or pay for two and take three, depending on the promotion.
Need to calculate something else?
These tools are often used alongside this calculator.
Percentage
The four most common percentage calculations in a single tool.
Percentage increase
Apply a percentage rise to any amount and see the exact difference.
VAT
Add VAT or sales tax to a net amount at whatever rate you need.
Margin
A clear distinction between margin on price and markup on cost.
Selling price
Set your price from the cost and the margin or markup you want to achieve.
Compound interest
How much your money grows with regular contributions, and what it is really worth once inflation and fees…