Discount Calculator
Enter a price and a discount to see the final price and savings instantly — including stacked discounts applied one after another.
Stacked / multiple discounts
Add another discount to apply on top of the one above — each new discount is applied to the price after the previous one, not to the original price.
This calculator is for estimation purposes only. It doesn't account for taxes, shipping, coupon exclusions or store-specific rounding rules — always confirm the final price at checkout.
How it works
Enter the original price
Type the price before any discount — or the final price, if that's what you know instead.
Enter the discount
Add a percentage off, or switch modes to work out what percent a sale price implies.
Stack more if needed
Add extra discounts to see the real final price when multiple offers apply one after another.
What people use a discount calculator for
Sale math looks simple until a second discount gets stacked on top.
Checking a sale is really a good deal
Stacking a coupon on a clearance price
Comparing two different sale prices
Pricing a sale as a seller
Working backward from a sale price
Why stacked discounts aren't the same as adding percentages
A "20% off, plus an extra 10% off" promotion feels like it should add up to 30% off — but it doesn't, and the gap isn't a rounding quirk, it's how percentages compound. The second discount is applied to the price that's already been reduced by the first one, not to the original price. On a $100 item: 20% off brings it to $80. Take an extra 10% off that $80 — not off the original $100 — and you lose $8, landing at $72. A flat 30% off $100 would land at $70. Two dollars might not sound like much on a $100 item, but the gap grows with the price and with how many discounts get stacked, and retailers rely on shoppers doing the "just add the percentages" math in their head instead of the real one.
The good news is stacking is order-independent: applying 20% then 10% lands on exactly the same final price as applying 10% then 20%, because multiplying by (1 - 0.20) and then (1 - 0.10) gives the same result regardless of which order you multiply in. What matters isn't the order, just that each discount is applied to the running price, not the original one — which is exactly what the stacked-discounts section above does for you, one input row per discount.
The "effective discount" figure translates a stack of discounts back into a single number for comparison — the one flat percentage that would have produced the same final price. It's useful for sanity-checking a promotion at a glance ("that combo is really only a 28% deal, not 30%") without doing the multiplication by hand every time.
Frequently asked questions
How is the final sale price calculated?
The calculator multiplies the original price by (1 minus the discount as a decimal). A $50 item at 20% off is $50 x 0.8 = $40. The amount saved is simply the original price minus that final price.
Why isn't 20% off plus an extra 10% off the same as 30% off?
Because each discount is applied to the price that's already been reduced by the one before it, not to the original price. $100 at 20% off is $80; take an extra 10% off that $80, not the original $100, and you get $72 — a 28% total discount, not 30%. Stacking two discounts is always slightly less generous to the shopper than adding their percentages together and applying that once.
Does the order of stacked discounts matter?
No — multiplying by (1 - 20%) then (1 - 10%) gives exactly the same final price as multiplying by (1 - 10%) then (1 - 20%), since multiplication doesn't care about order. What does matter is that each one is applied to the running price, not the original price, every time.
Can I work out the discount percent if I only know the original and sale price?
Yes — switch to "I know the final price" mode, enter both prices, and the calculator solves for the discount percent and amount saved for you, using the same math in reverse.
What does "effective discount" mean for stacked discounts?
It's the single discount percent that would have produced the same final price as your combination of stacked discounts. For 20% then an additional 10%, the effective discount is 28% — not the 30% you'd get by adding the two percentages together.
Is this discount calculator free to use?
Yes, completely free, with no account or sign-up, and it runs entirely in your browser.