Discount and percentage calculator
Calculate price after discount, discount amount, percentage change, percentage difference, or work out the original price before a discount.
Required fields are marked with an asterisk (*).
A multi-purpose tool for discounts and percentages: work out the final price after a discount, the discount amount, the percentage increase or decrease between two values, the percentage difference between them, or the original price when you know the final price and the discount rate. Choose the calculation type and the relevant fields appear automatically.
Formula
Price after discount = original × (1 − rate). Discount amount = original × rate. Percentage change = (B − A) ÷ A × 100. Percentage difference = |A − B| ÷ ((A + B) ÷ 2) × 100.
When is this useful?
Use it when shopping and comparing offers to find the final price after discounts, when analysing price increases or decreases between two periods, or when you need to work out the original price behind a discounted figure.
Worked example
Example using the calculator’s values: an item with an original price of 1,000 UAE dirhams at a 20% discount.
The discount amount is 200 dirhams.
The price after discount is 800 dirhams.
Assumptions
- Standard mathematical formulas are used, without extra commercial considerations.
- In the percentage-change mode, the first value is used as the base.
- Percentage difference is calculated from the average of the two values and is always positive.
- Prices are treated at their nominal value, without tax or additional discounts unless included in the inputs.
Common mistakes
- Applying the discount to the final price instead of the original price.
- Mixing up percentage change and percentage difference: the first uses the first value as the base, the second uses the average of the two values.
- Assuming consecutive discounts add up, while a 10% then 10% discount is not equal to 20%.
- Believing that an increase and a decrease by the same percentage return a value to its original amount.
Frequently asked questions
Why is 10% then 10% not the same as a single 20% discount?
Because the second discount applies to the already-discounted price, leaving you at 81% of the original rather than 80%.
How do I work out the original price from the final price?
Divide the final price by (1 − discount rate), which is what the calculator does in the “original price” mode.
What is the difference between percentage change and percentage difference?
Percentage change compares the second value with the first as the base, while percentage difference compares the two values with their average and is always positive.
Do the results include VAT?
No, the calculator works exactly on the prices you enter; tax is calculated separately.
Methodology and review
Results are estimates for informational purposes only and do not constitute financial or binding pricing advice.