Quick examples
- 200 with 25% off = 150 (you save 50).
- 89.99 with 15% off = 76.49.
- 20% off then an extra 10% off = 28% off in total.
Quick answers
How do I calculate a discount?
Sale price = price × (1 − discount ÷ 100). Savings = price − sale price.
Percentage formulas
- X% of Y = X ÷ 100 × Y. Example: 15% of 200 = 30.
- X is what % of Y = X ÷ Y × 100. Example: 30 of 200 = 15%.
- Percent change = (new − old) ÷ old × 100. From 80 to 100 = +25%; from 100 to 80 = −20%.
- Discount: price × (1 − discount ÷ 100). 200 with 25% off = 150.
Frequently asked questions
Why is a 20% drop not undone by a 20% rise?
Because the second percentage is taken from a smaller number: 100 − 20% = 80, and 80 + 20% = 96. To get back to 100 you need +25%.
How do I calculate VAT?
Use “add a percentage” with your VAT rate, or the dedicated VAT calculator (Arabic) for invoices and extracting VAT from a total.