Discount Calculator
Enter a price and a discount to get the sale price, how much you save and the real percentage off when two discounts are combined.
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A sign that says “25% off, plus an extra 10% at the till” sounds like 35% off. It isn’t. This discount calculator shows the real sale price, how much you save and the true total discount, with optional sales tax on top.
How to use the discount calculator
- Enter the original price of the item.
- Enter the discount percentage.
- If there is a second offer, such as a coupon or a member discount, enter it as the extra discount. Leave it at 0 otherwise.
- Add your local sales tax rate if you want the price you will actually pay at the till.
The results show the final price, your saving, the combined discount as a single percentage and the price before tax.
The discount formula
For a single discount:
Sale price = Price × (1 − Discount ÷ 100)
Saving = Price − Sale priceWhen a second discount is applied to the already reduced price:
Sale price = Price × (1 − D1 ÷ 100) × (1 − D2 ÷ 100)
Total discount % = (1 − Sale price ÷ Price) × 100Worked example
A jacket costs $120. It is 25% off, and you have a coupon for an extra 10%.
- After the first discount: 120 × 0.75 = $90
- After the coupon: 90 × 0.90 = $81
- You save 120 − 81 = $39
- Total discount = 39 ÷ 120 = 32.5%, not 35%
If your sales tax is 8%, you pay 81 × 1.08 = $87.48 at the till.
Common stacked discounts
| First discount | Extra discount | Real total discount |
|---|---|---|
| 20% | 10% | 28% |
| 25% | 10% | 32.5% |
| 30% | 20% | 44% |
| 50% | 20% | 60% |
| 50% | 50% | 75% |
“50% off, then another 50% off” leaves you paying a quarter of the price, not nothing.
Finding the original price
If you only know the sale price and the discount, divide instead of multiplying. An item on sale for $63 at 30% off had an original price of 63 ÷ 0.70 = $90. This is useful for checking whether a “was” price on a label is honest.
Percent off or money off?
Shops often let you choose between a percentage coupon and a fixed amount, such as 15% off or $20 off. The break-even point is the price where both give the same saving: divide the fixed amount by the percentage as a decimal. Here that is 20 ÷ 0.15 ≈ $133. Below $133 the $20 coupon saves more, and above it the 15% coupon wins.
Tips for smart shopping
- Compare the final price, not the percentage. 40% off a $150 item costs more than 20% off a $100 one.
- Check the reference price. Some retailers raise the “original” price before a sale so the discount looks bigger. Look at price history if you can.
- Watch out for minimum spends. A coupon that only works above $100 may tempt you to buy more than you need.
- Count shipping. A big online discount can disappear if shipping costs $15 and a local store charges nothing.
- Percentage or fixed amount? On cheap items a fixed coupon such as $10 off often beats a percentage. On expensive items the percentage usually wins.
Frequently asked questions
How do I calculate a percentage discount?
Multiply the price by the discount percentage and divide by 100 to get the saving, then subtract it from the price. A 25% discount on $120 saves $30, so the sale price is $90.
Are two discounts of 25% and 10% the same as 35% off?
No. The second discount is taken from the already reduced price, so together they give 32.5% off, not 35%. Stacked discounts are always worth a little less than their sum.
Does the order of stacked discounts matter?
For two percentage discounts, no. Taking 10% then 25% gives the same price as 25% then 10%. The order does matter when one of them is a fixed amount, such as $10 off.
Is sales tax charged on the original price or the discounted price?
In most US states, sales tax is charged on the discounted price when the store gives the discount. Manufacturer coupons can be different in some states, where tax may be charged on the price before the coupon.