Discount Calculator
Find the sale price and how much you save, with optional sales tax.
How to calculate a discount
A discount takes a percentage off the original price.
- Savings = original price × discount ÷ 100
- Sale price = original price − savings
- Total with tax = sale price × (1 + tax rate ÷ 100)
Sales tax is normally charged on the price after the discount, which is how this calculator works.
Worked examples
- 25% off $120: you save $30 and pay $90.
- With 8% sales tax: $90 × 1.08 = $97.20.
- Two discounts in a row: 20% off, then 10% off, takes 28% off in total, not 30%, because the second discount applies to the already reduced price (0.80 × 0.90 = 0.72).
- Finding the original price: if an item costs $75 after 25% off, the original price was $75 ÷ 0.75 = $100.
Frequently asked questions
How do I find the original price from the sale price?
Divide the sale price by 1 minus the discount as a decimal. For 25% off, divide by 0.75. A $75 sale price means a $100 original price.
How do I add two discounts together?
Apply them one after the other. Multiply the remaining shares: 20% off then 10% off leaves 0.80 × 0.90 = 0.72 of the price, so the total discount is 28%.
Is a percent off better than a dollar amount off?
It depends on the price. Compare the actual money saved. 20% off a $200 item saves $40, which beats $30 off, but on a $100 item 20% saves only $20.
Is sales tax calculated before or after the discount?
In most places tax is charged on the discounted price. Some stores and coupon types work differently, so check your receipt if the total looks off.
Results are estimates for general information.