Why stacked discounts disappoint
A second discount applies to the already-reduced price, not the original. On a 100 item, 30% off leaves 70, and the extra 10% comes off that 70, saving just 7 more. Final price 63, effective discount 37%, not the 40% your intuition adds up to.
Retailers know this, which is why stacked offers are so common in marketing. The bigger the first discount, the less each additional one is actually worth.
Judging whether a deal is real
A discount is only as real as the reference price. Anchoring to an inflated original price is the oldest trick in retail, so what matters is the final price against what you would happily pay, and against the price history if you can find it.
Per-unit price is the other honest comparator: a discounted large pack can still cost more per unit than an undiscounted regular one. Our unit price calculator handles that comparison directly.
Frequently asked questions
Is 30% off plus 10% off the same as 40% off?
No. The second discount applies to the reduced price, so the combination is 37% off. Stacked discounts always total less than their sum.
How do I calculate the price before a discount?
Divide the sale price by 1 minus the rate. Something selling at 63 after 37% off had an original price of 63 ÷ 0.63 = 100.
Should tax be applied before or after the discount?
In virtually all systems, tax is charged on the actual selling price after discounts, which is how this calculator applies it.
What order do stacked discounts apply in?
Order does not matter mathematically: 30% then 10% equals 10% then 30%. Both multiply to the same 0.63 factor.
How do I compare percent-off against amount-off coupons?
Convert both to final prices. On a 80 item, 25% off beats a flat 15 off (60 versus 65), but on a 50 item the flat coupon wins.
Is a bigger pack always the better deal?
Not automatically. Divide price by quantity for each option and compare per-unit costs; discounts on large packs sometimes still lose.