💡 Did You Know?A 20% discount followed by another 20% equals 36% total off — not 40%!
Stacked Discount — FAQs
What is a stacked discount?
A stacked (or sequential) discount applies two percentage reductions one after the other. Each subsequent discount hits the already-reduced price, not the original — so the true combined saving is always less than simply adding the two percentages together.
Is 20% off then 20% off the same as 40% off?
No. Two 20% discounts applied sequentially equal 36% total off. The formula is: effective = 1 − (1 − d₁) × (1 − d₂). Here: 1 − 0.80 × 0.80 = 0.36. Retailers rely on this mismatch to advertise impressive-sounding stacks while protecting their margins.
How do I calculate a stacked discount manually?
Step 1: Multiply the original price by (1 − d₁ ÷ 100) to get the price after the first discount. Step 2: Multiply that result by (1 − d₂ ÷ 100) to get the net price. Step 3: Multiply the net price by (1 + tax ÷ 100) for the final price. This calculator handles all three steps in real time.
Why does the second discount apply to the reduced price?
By convention — and legal requirement in most markets — each successive discount applies to the current price at that stage of the transaction. This is why "an extra 10% off already-reduced items" is a smaller saving than it sounds.
Does this calculator support sales tax and VAT?
Yes. Enter your local tax rate and it will be applied to the post-discount net price. The four sub-stats show net price (pre-tax), tax amount, price after only the first tier, and your total saving — so you see every step of the calculation.