CAL-001
Discount Calculator
Enter what something costs and the percentage being taken off. The calculator shows both the amount saved and the price you actually pay.
- Free
- No signup
- Private · runs locally
How to calculate a discount
- Enter the original price before any reduction.
- Enter the discount percentage - type 20 for 20% off.
- Read the discount amount and the final price. Both update as you type.
The discount formula
Discount amount = Original price × (Discount % ÷ 100). Final price = Original price − Discount amount.
A shortcut worth knowing: 20% off means you pay 80%, so you can multiply the price by 0.8 directly. The same trick works for any percentage - subtract it from 100 and move the decimal point two places left.
Discounts do not stack the way people expect. Taking 20% off and then a further 10% off is not 30% off: the second reduction applies to the already-reduced price, giving 28% off in total.
Frequently asked questions
How do I calculate 20% off a price?
Multiply the price by 0.20 to get the saving, or by 0.80 to get what you pay. On a $50 item that is $10 off and $40 to pay.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount ÷ 100). A $40 item that was 20% off started at 40 ÷ 0.8 = $50.
Does this include sales tax or VAT?
No. The calculation is applied to the price you enter. If you enter a tax-inclusive price, the result is tax-inclusive too.