Discount Calculator – Percent Off & Final Price
See exactly what you save with any percent-off deal, and what the final price is once optional sales tax is added.
The price before any discount.
Added on the discounted price if you enter it.
Final price
$80.00
- You save
- $20.00
- Price after discount
- $80.00
- Final price
- $80.00
Add a sales tax rate above to see the final checkout price.
For informational purposes only — not financial or tax advice.
How the discount calculator works
Enter the original price and the percent-off figure; the tool returns the amount saved and the price you will actually pay. If you add a sales tax rate, tax is applied after the discount — which is how most US retailers ring up promotions.
Formula
saved = price × (discount ÷ 100) final = price − saved w/tax = final × (1 + tax ÷ 100)
20% off $50 saves $10, so you pay $40. With 8% sales tax: $40 × 1.08 = $43.20 at the register.
The double-discount trap
Stacked discounts multiply instead of adding. “20% off, then an extra 10% off” sounds like 30% off, but $100 becomes $80 and then $72 — an effective 28% discount. The second percentage applies to the already-reduced price. Run both numbers before you assume a sale is generous.
When a bigger percent is worth less
Percentages only matter relative to the base price. 50% off a $40 item saves you $20; 25% off a $120 item saves $30. Comparing absolute savings — which this tool shows — stops the classic “bigger percentage must be better” mistake.
Worked examples
- Simple percent-off: $80 at 15% → save $12.00, final price $68.00.
- With sales tax: $100 at 20% off with 8% tax → $80.00 after discount, + $6.40 tax = $86.40 final.
- Stacked discounts: $200 at 30% off, then an extra 20% off → $200 → $140 → $112, an effective 44% discount, not 50%.
Frequently asked questions
How do I calculate a percentage discount?
Multiply the original price by the discount percentage, then subtract it from the original. For 20% off $50: $50 × 0.20 = $10 off, so the final price is $40.
How do I add sales tax after a discount?
Apply the discount first, then calculate tax on the discounted price. A $100 item with 20% off and 8% tax: $100 − $20 = $80, then $80 × 1.08 = $86.40 final.
What is 20% off $50?
20% of $50 is $10, so you pay $40 and save $10. The calculator shows the saving and final price for any percentage and amount instantly.
How does a double discount work?
Successive discounts multiply rather than add. 20% off followed by another 10% off is not 30% off: $100 → $80 → $72, an effective 28% discount. Retailers often label this 'extra 10% off sale prices'.
Do stores tax the original or discounted price?
In most US states, sales tax applies to the price actually charged after discounts and coupons, though rules for manufacturer coupons can differ. Check your state's Department of Revenue for specifics.