Reckonary / Everyday / Stacked discount
Final price
Stores love a layered sale: "30% off, then an extra 20% at checkout." It reads like 50% off, but it isn't. Each discount comes off the price the previous one already lowered, so the deals multiply instead of adding up. This calculator does that math for you and shows the real final price, how much you actually save, and the true effective discount in a single percentage.
A percentage is always taken from whatever the price is at that moment, not from the original sticker. So the first discount shrinks the price, and the second discount is then applied to that smaller number — a smaller base means a smaller dollar amount comes off. That is why two deals never add up to their combined percentage.
The clean way to see it is to track what you keep rather than what you save. After 20% off you keep 80% of the price; after another 10% off you keep 90% of that. Multiply the two and you keep 0.80 × 0.90 = 0.72, so you pay 72% and save 28% — not the 30% you'd get by adding 20 and 10. The deeper the discounts, the wider this gap: a "50% then 50%" sale sounds free but leaves you keeping 0.50 × 0.50 = 0.25, so you still pay a quarter of the price. The stacked discounts guide walks through the same idea one step at a time.
Enter the original price, then set each discount with the sliders. The tool applies them in sequence: it takes the price, removes the first discount, removes the second from what's left, and the third after that. Leave a slider at zero if you only have one or two deals. The ledger bar under the result shows your effective discount — the single percent-off that would land on the same final price, so you can compare a stacked offer against a plain one at a glance.
Take a $100 jacket with 20% off and an extra 10% at the register. First the price drops to $80, then 10% off $80 brings it to $72. You save $28, which is a 28% effective discount — noticeably less than the 30% you'd get by simply adding the two numbers.
Bigger deals widen the gap. A $100 item at 50% off then an extra 20% lands at $40 — a 60% effective discount, not 70%. Stack a third deal, say a $200 coat at 40% then 25% then 10% off, and you end up at $81: you save $119, an effective discount of 59.5% rather than the 75% those three numbers add to. The single effective percentage is the honest figure to shop with.
Use the effective discount to settle the classic checkout question: is "30% off then 20% off" better than one flat "40% off" coupon? On a $100 cart the stacked version comes to $56 — a 44% effective discount — so it beats the single 40% coupon. Whenever you're handed competing offers, convert each to its effective percentage and the bigger one wins, no matter how many layers are involved.
Is 20% off then 10% off the same as 30% off?
No. Stacked discounts multiply rather than add. 20% off then 10% off leaves you paying 80% of 90%, which is 72% of the price — a 28% effective discount, not 30%.
How do I work out the final price by hand?
Multiply the price by what's left after each discount. For $100 with 20% then 10%, that's 100 × 0.80 × 0.90 = $72. Apply each discount to the running total, one after the other.
Does the order of the discounts matter?
No. Because the percentages are multiplied together, swapping the order gives the exact same final price. 20% then 10% equals 10% then 20%.
What is the effective discount?
It's the single percent-off that would give the same final price as all your stacked deals combined. It's always less than the sum of the individual discounts.
Last reviewed June 2026. Stacked discounts multiply, so two 20% offs are not 40% off.