Discount Calculator
Calculate sale prices, stacked discounts, tax, and original prices with a free browser-only discount calculator that updates as you type.
About Discount Calculator
Overview
Discount Calculator helps you figure out the final price of an item after a percentage discount, including support for stacked discounts, sales tax, and a reverse mode that recovers the original price from the amount you actually paid. It is designed for quick shopping math at the register or while comparing deals online. The calculator updates results live as you type, so you can experiment with different discount combinations without reloading the page.
Features
- Two calculation modes: forward (original to final) and reverse (final to original)
- Support for stacked discounts that combine multiplicatively
- Optional tax percentage applied to the discounted price
- Live updating results as you change any input
- Clear breakdown of savings, tax, and effective discount rate
- Quick reference stats including effective rate and savings per $100
- Responsive design that works on phones, tablets, and desktops
- Completely browser-based - prices never leave your device
How to Use
- Pick a mode: "Calculate Final Price" or "Find Original Price"
- Enter the original or discounted price and the discount percentage
- Optionally enable a second stacked discount to model layered promotions
- Optionally enable a tax percentage to see the final total after tax
- Review the final price, amount saved, and detailed breakdown
FAQ
How are stacked discounts combined?
Stacked discounts are multiplied rather than added. A 20% discount followed by a 10% discount on a $100 item is $100 x 0.80 x 0.90 = $72, which equals a single 28% discount. This is the standard way retailers layer multiple promotions.
Is tax added before or after the discount?
Tax is added after the discount. The discount is applied to the original price first, then tax is calculated on the discounted amount. This matches the way most retail stores and online shops compute final totals at checkout.
How does reverse mode work?
In reverse mode you enter the price you actually paid and the discount percentage. The calculator divides the paid price by (1 - discount) to recover the original price. If tax is enabled it first strips the tax component so the recovered price reflects the pre-tax, pre-discount value.
Can I find the original price from a receipt that already includes tax?
Yes. Enable the tax option and enter the same tax rate that appeared on your receipt. The calculator will remove the tax, then reverse the discount to give you the original sticker price. This is useful for verifying sale prices or filing price-matching requests.
Is my financial information stored anywhere?
No. All calculations happen entirely in your browser using client-side JavaScript. Prices, discount percentages, and tax rates are never sent to a server, logged, or stored in cookies, so your shopping data stays on your device.