Discount and price increase calculator

How do you calculate a discount?

Final price = price × (1 − discount ÷ 100). With a €100 price and a 20% discount: 100 × 0.80 = €80. The discount is €20 and the final price €80.

How do you calculate a price increase?

Final price = price × (1 + increase ÷ 100). With €100 and a 15% increase: 100 × 1.15 = €115.

How do I calculate the percentage change between two prices?

Change = (final price − starting price) ÷ starting price × 100. From €80 to €100: 20 ÷ 80 = +25%. From €100 to €80: −20 ÷ 100 = −20%. That is why a 20% discount is offset by a 25% increase, not 20%.

What if I want the price including VAT to be a round number?

First work out the price without VAT with this calculator and add VAT with the VAT calculator; that way you see the final price your customer will see.

Worked example: a 20% sale

A €100 product with a 20% discount costs €80. To get back to €100 from €80, a 20% increase is not enough (€96): you need 25%, because the 25% applies to €80.

How to use this tool

1. Enter the starting price.
2. Choose a discount, an increase or the change up to a final price.
3. Read the final price and the change.

Frequently asked questions

How do I calculate the price after a discount?

Multiply the price by (1 − discount ÷ 100). At 20%, by 0.80.

How do I calculate the percentage between two prices?

(Final price − starting price) ÷ starting price × 100.

Why does a 20% increase not offset a 20% discount?

Because the second percentage applies to a lower price. You need a 25% increase to recover the starting price.

Does it include VAT?

No: it applies to what you type. If your price includes VAT, the result does too.

Keep reading

• How to calculate Spanish VAT on an invoice
• How to read a Spanish invoice
• Freelance hourly rate calculator
• Profit margin and markup calculator
• Break-even point calculator
• Spanish VAT calculator
• All free tools

Reviewed on 6 November 2026. Indicative result: it does not replace an advisor's advice.