A bold discount can be useful, but the percentage alone never tells the whole story. The final price, normal market price, product size, and your actual need all matter.
Start with the final price
Multiply the original price by the percentage left after the discount. A 30% discount means you pay 70%. On a $90 item, 0.70 × $90 gives a sale price of $63.
Understand stacked discounts
A further 20% off after 30% off means paying 70% and then 80% of the original: 0.70 × 0.80 = 0.56. You pay 56%, so the combined reduction is 44%, not 50%.
Compare unit prices
For multipacks and different sizes, divide the final price by the number of units, ounces, or grams. A larger headline discount can still produce a higher unit price.
Include conditions and extra costs
Shipping, memberships, minimum spends, return restrictions, and coupons that exclude certain items can change the real value. Compare the amount that will actually leave your account.
A calculator is often the quickest way to check your mental math. The important part is using the right starting value.
Open a calculator →Common questions
Does a higher discount always mean a better deal?
No. The original price may be inflated, or another retailer may have a lower regular price.
How do I compare different package sizes?
Calculate the price per common unit after all discounts and fees.
Should I include sales tax?
Include it when comparing your final out-of-pocket cost, especially if the alternatives are taxed differently.
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