How it works
Enter the original price and add each discount as a percentage. Choose "stacked" to apply them one after another — each discount comes off the already-reduced price, the way most "take an extra 20% off" offers work — or "additive" to add the percentages and take them off in one go. Add an optional tax rate to see the final amount you'd actually pay. The calculator shows the final price, the total you saved, and the single "effective discount" that would produce the same result. Everything runs locally in your browser.
Discount Stack Calculator
Combine multiple discounts — stacked or additive — plus tax.
FAQ
What's the difference between stacked and additive discounts?
Stacked discounts are applied one after another, each to the already-reduced price, which is how most "extra % off" promotions work. Additive discounts simply add the percentages together and take that off once. Stacking always gives a smaller total discount than adding the same percentages.
Can I add sales tax?
Yes. Enter a tax percentage and it's applied to the discounted price, so the final figure reflects what you'd actually pay.
What is the effective discount?
It's the single percentage off that would produce the same final price before tax — a handy way to compare stacked deals against a plain one-off discount.
Is anything uploaded?
No. The calculation runs entirely in your browser. Nothing you enter is sent to a server.
Related tools
Sales Tax & Discount · Percentage Change · Percentage Calculator