Stack percentages correctly
Each successive discount applies to the already reduced price. A fixed coupon is then subtracted under this model, so its relative value grows as the price falls.
Retail discount and unit-economics analysis
Audit stacked discounts through tax, shipping, cashback and true unit price.
Solve basic percent-off questions, compare best-single versus sequential promotions, reverse-engineer the original price and test both shopper savings and merchant margin.
Decision guide
How to compare a real discount
The advertised percentage is only one part of the transaction. A useful comparison follows the price through every promotion and checkout charge, then normalises it by quantity or usable unit.
Compare the checkout
Tax, shipping and cashback can reverse an apparent advantage. Compare final net order cost with the competitor using the same quantity and tax assumptions.
Normalise the package
Unit price exposes different pack sizes and quantities. Budget quantity is based on checkout cost, while merchant margin uses revenue after the modeled promotion.
Cashback arrives later
Cashback may require activation, eligible payment methods or waiting periods. The bank balance at checkout is the gross amount, not the later net amount.
Returns can change the deal
A return may allocate coupons across items or reverse cashback. Multi-buy promotions can also change when part of the order is returned.
Margin is simplified
Merchant margin here subtracts entered item cost and cashback from discounted product revenue. It excludes labour, fulfilment, payment processing, overhead and returns.
Simple by design
Three steps to a clearer number.
Enter your details
Use realistic values in each field. You can change them anytime.
Calculate instantly
The formula runs locally, so there is no account or waiting time.
Use the result
Treat the answer as a practical estimate for your next decision.