How to calculate a discount
To find a sale price, multiply the original price by the discount percentage to get the savings, then subtract that from the original. For example, 25% off $120 saves $30, for a sale price of $90. This calculator also adds sales tax, so you see the true amount you’ll actually pay at the register — not just the shelf sticker.
The formulas
Sale price = Price × (1 − discount%/100). Final total = Sale price × (1 + tax%/100). Set sales tax to 0% if you just want the discounted price.
Quick reference: what you pay after a discount
| Discount | $50 item | $100 item | $200 item |
|---|---|---|---|
| 10% off | $45.00 | $90.00 | $180.00 |
| 20% off | $40.00 | $80.00 | $160.00 |
| 25% off | $37.50 | $75.00 | $150.00 |
| 30% off | $35.00 | $70.00 | $140.00 |
| 50% off | $25.00 | $50.00 | $100.00 |
“Extra 20% off”: how stacked discounts really work
When a store takes an extra percentage off an already-reduced price, the discounts don’t simply add up. A $100 item at “40% off, then an extra 20% off” is not 60% off. It’s $100 → $60 (after 40%) → $48 (after another 20%). That’s a real discount of 52%, not 60%. Stacked percentages always come out to less than the sum, because the second cut applies to a smaller number. To check a stacked deal, run the first discount here, then use the result as the new original price and apply the second.
Does the discount or the tax come first?
The discount always comes first. Stores reduce the price, then charge sales tax on the discounted amount — which is exactly what this calculator does. So a $120 jacket at 25% off in a 7% tax area is $90 after discount, then $96.30 out the door. You never pay tax on money you saved.
Is the deal actually good?
A useful habit: convert “percent off” into dollars saved, which this tool shows directly. “15% off” sounds modest but is $75 on a $500 purchase; “50% off” a $6 item is $3. The percentage grabs attention, but the dollar figure tells you whether it’s worth acting on. For the percentage math on its own, see the percentage calculator; for splitting a discounted bill, the tip calculator handles the divide.
Frequently asked questions
How do I calculate percent off?
Multiply the original price by the percentage and divide by 100 to get the dollars saved, then subtract that from the price. 25% off $120 saves $30, for a $90 sale price. This tool does it instantly and adds tax too.
Is sales tax applied before or after the discount?
After. Stores reduce the price first, then charge sales tax on the discounted amount — which is what this calculator does. You never pay tax on the money you saved.
How do stacked discounts work, like '40% off plus an extra 20%'?
They multiply, they don't add. $100 at 40% off is $60, then 20% off that is $48 — a real discount of 52%, not 60%. Stacked percentages always total less than their sum.
What does 25% off actually save me?
A quarter of the price. On $37.50 for a $50 item, $75 for a $100 item, $150 for a $200 item. Enter your price above for the exact saving and final total.
How do I work out the original price from a sale price?
Divide the sale price by (1 minus the discount as a decimal). A $90 item at 25% off was 90 / 0.75 = $120 originally.
Is a bigger percentage always the better deal?
Not necessarily — convert it to dollars. 15% off a $500 purchase saves $75, while 50% off a $6 item saves $3. The dollar figure, which this tool shows, is what matters.