Discount Calculator
Discount Calculator is a free finance tool that runs directly in your browser with no account required.
About this tool
This calculator works out the real price after a sale discount, an extra stacked coupon, quantity, and sales tax. Because stacked discounts multiply rather than add, it reports the true effective discount along with your total savings, and a scenario table shows how the numbers move with a deeper discount or bigger coupon. Scenarios export to CSV.
How to use
- Enter the Original price and the advertised Discount %.
- Add an Extra coupon % if you are stacking a second code on top.
- Set Quantity and your Sales tax % if you want the out-the-door total.
- Check the sale subtotal, total with tax, effective discount, and savings, then use Download discount scenarios CSV to compare options.
Frequently asked questions
How are stacked discounts combined?
Sequentially, not additively. A 25% discount followed by a 10% coupon multiplies to a 32.5% effective discount — the coupon applies to the already-reduced price, and the tool reports this true combined rate.
Is sales tax charged on the original or discounted price?
On the discounted sale subtotal, after both the discount and the coupon are applied, which is how US retailers typically compute tax on sale items.
What do the scenario rows compare?
Your current setup against three variants: removing the extra coupon, raising the main discount by 5 points, and raising the coupon by 5 points, each with its own effective discount and total.
What limits apply to the inputs?
The discount and coupon each cap at 99%, the price cannot be negative, and quantity is treated as a whole number of at least 1.
Does this tool track what I am shopping for?
No. Prices are processed only in your browser and are never sent anywhere.
Are these final checkout prices?
They are estimates. Retailers may exclude items from stacking, apply coupons in a different order, or round differently, so verify at checkout.