Discount Calculator
What does 25% off actually cost? Get the sale price and savings for any discount — including “extra 20% off clearance” stacking — or flip it to find what percent off a marked-down price really is.
You pay
$60.00
You save
$20.00
Total off
25%
Mental shortcut: 10% is the price with the decimal moved one place left — build other discounts from it (20% = double it, 25% = a quarter off, 15% = 10% plus half again). Sales tax is usually charged on the discounted price, not the original.
How Discounts Work
A percent-off discount multiplies the price by (1 − rate): 25% off $80 is 80 × 0.75 = $60. Stacked discounts apply one after the other to the already-reduced price, which is why “30% off plus an extra 20% off” comes to 44% total — not 50%. Retailers count on shoppers adding the two numbers.
Formula
Sale price = Original × (1 − discount%) Stacked = Original × (1 − first%) × (1 − second%) Quick anchors on $100: 10% off → $90 30% off → $70 25% off → $75 50% off → $50 30% + extra 20% → $56 (44% off, not 50%)
Frequently Asked Questions
How do I calculate 20% off a price?
Multiply the price by 0.80: a $45 item at 20% off costs $36. Mentally, find 10% by moving the decimal one place left ($4.50), double it ($9), and subtract. The same pattern works for any discount — multiply by (1 minus the rate).
Is 30% off plus an extra 20% off the same as 50% off?
No — stacked discounts multiply rather than add. The extra 20% comes off the already-reduced price: $100 → $70 → $56, which is 44% off, not 50%. Retailers stack discounts precisely because the combined deal sounds bigger than it is.
How do I find the original price from a sale price?
Divide by (1 minus the discount rate). A $60 item marked 25% off was originally $60 ÷ 0.75 = $80. Adding 25% back to $60 ($75) is the common mistake — it undershoots because the percentage was taken off the larger original number.
Is sales tax charged on the discounted price or the original?
Store discounts and coupons reduce the taxable price, so you pay tax on what you actually pay the register. The wrinkle is manufacturer coupons — in some states the store is reimbursed, so tax applies to the pre-coupon price.