How to use it
- Enter the original price and the percentage off, or tap one of the common discounts.
- For deals like "extra 20% off clearance", open the extra section and add the second discount.
- Add your sales tax rate if you want the real checkout total.
Discount formulas
Savings = Price × Discount ÷ 100
Sale price = Price × (1 − Discount ÷ 100)
Two discounts = Price × (1 − D1 ÷ 100) × (1 − D2 ÷ 100)
Final price = Sale price × (1 + Tax ÷ 100)
Worked example
A jacket is listed at $129.99 with 30% off. You save $39.00 and the sale price is $90.99. With an extra 20% off clearance, the price drops to 90.99 × 0.80 = $72.79, so your total saving is $57.20, or 44% of the original price. Add 7% sales tax and you pay $77.89 at the register.
Stacked discounts don't simply add up
This is the part most shoppers get wrong. "30% off plus an extra 20% off" is not 50% off. The second discount applies to the already reduced price, so the true saving is 44%. The gap grows with bigger numbers: 50% off plus an extra 50% off is 75% off, not free. The calculator shows the combined discount on the Total discount line so you can compare offers honestly.
Percent off versus dollars off
A flat "$25 off" coupon is worth more than "20% off" on anything under $125, and less above it. If a store offers a choice, do the quick division: the break-even price is the dollar amount divided by the percentage as a decimal. For $25 and 20%, that is 25 ÷ 0.20 = $125.
Is the discount real?
Retailers sometimes advertise a percentage off a list price that almost nobody paid. Before assuming a deal is good, check the recent selling price rather than the tag price. Browser price-history tools help for online shopping. The math on this page tells you what you will pay, not whether the starting price was fair.
Sales tax and discounts
In most states, sales tax is charged on the price after a store discount, because that is what you actually paid. Manufacturer coupons can work differently: in some states, the retailer is reimbursed by the manufacturer, so tax is calculated on the pre-coupon price. If an odd tax amount shows on your receipt, this is often the reason. Check your state revenue department for the exact rule.
Buy one, get one and other deals
BOGO free is a 50% discount if you actually need both items. "Buy one, get one 50% off" is a 25% discount across the two items. To compare with a plain percentage sale, work out the price per item after the deal and put that number into the calculator as the sale price. The same trick works for bundles: divide the bundle price by the number of items you will really use.
A note on financing offers
Discounts that come with store financing deserve extra care. A 10% discount that pushes you into a card with deferred interest can cost more than it saves if the balance is not cleared before the promotional period ends. Compare the saving with the interest you would pay, using the compound interest calculator if you need the math.
Frequently asked questions
How do I calculate a discount?
Multiply the price by the discount as a decimal to get the savings, then subtract that from the price. 30% off $80 saves $24, so you pay $56.
What is 30% off plus an extra 20% off?
It equals 44% off the original price, because the second discount applies to the already reduced price.
Is sales tax charged before or after the discount?
Usually after a store discount, on the amount you actually pay. Manufacturer coupons can be treated differently by state.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount as a decimal). A $56 item at 30% off started at $80.
Which is better, $25 off or 20% off?
The dollar coupon wins below $125 and the percentage wins above it. Divide the dollar amount by the percentage as a decimal to find the break-even price.
Last reviewed on by the Dailycaltor team.