See what a deal really costs
Store sales, coupon codes, member offers and clearance markdowns stack up, and the advertised percentages can be misleading. This calculator gives you the sale price, how much you save, the true discount when offers combine, and the total with sales tax you will pay at checkout.
The formulas
- Price after one discount = original price × (1 − discount ÷ 100).
- Price after two stacked discounts = original price × (1 − discount 1 ÷ 100) × (1 − discount 2 ÷ 100).
- True discount = 1 − (1 − discount 1) × (1 − discount 2).
- Savings = original price − sale price.
- Total with tax = sale price × (1 + sales tax ÷ 100).
- Original price from a sale price = sale price ÷ (1 − discount).
Worked example: a $120 jacket, 30% off plus a 10% coupon
- After the sale discount: 120 × 0.70 = $84.
- After the coupon: 84 × 0.90 = $75.60.
- Savings: 120 − 75.60 = $44.40.
- True discount: 1 − 0.70 × 0.90 = 0.37, so 37%, not 40%.
- With 7% sales tax: 75.60 × 1.07 ≈ $80.89 at checkout.
Price by discount (with the extra 10% coupon and 7% tax)
| Discount | Price after discounts | Savings | Total with tax |
|---|---|---|---|
| 10% off | $97.20 | $22.80 | $104.00 |
| 20% off | $86.40 | $33.60 | $92.45 |
| 25% off | $81.00 | $39.00 | $86.67 |
| 30% off | $75.60 | $44.40 | $80.89 |
| 40% off | $64.80 | $55.20 | $69.34 |
| 50% off | $54.00 | $66.00 | $57.78 |
| 70% off | $32.40 | $87.60 | $34.67 |
Smart shopping habits
- Compare final prices, not percentages: 50% off an inflated list price can be worse than 20% off elsewhere. Price-history browser extensions help spot fake markdowns.
- Watch “up to” claims: “up to 70% off” often applies to only a handful of items.
- Count shipping and return costs when shopping online.
- Treat multi-buy offers as discounts: buy two, get one free is 33.3% off each item, but only a saving if you need all three.
- Check coupon order: when a store applies a fixed-dollar coupon before a percentage discount, you pay less than the other way round.
UK and EU shoppers
In the UK and the EU, shelf prices already include VAT, so set the sales tax field to 0. EU rules under the Omnibus Directive require stores to show the lowest price charged in the previous 30 days when they advertise a reduction, which makes comparisons more honest.
Quick mental math
For 20% off, multiply by 0.8; for 25% off, by 0.75; for 30% off, by 0.7; for 40% off, by 0.6. Two 50% discounts do not make an item free: you still pay 25% of the original price.