Calculate a sale price, reverse a discount, or stack multiple offers and tax in the order checkout applies them.
Change the inputs that matter to your decision. Optional assumptions stay collapsed until you need them.
Switch modes instead of rearranging the formula yourself.
Sequential discounts multiply; 20% then 10% is 28% off, not 30%.
The effective discount is 25.0%, before any displayed sales tax.
Coupon exclusions, minimum spends, shipping, and taxability vary by retailer.
Practical notes about the inputs, assumptions, and result.
Each later discount applies to an already reduced price, so 20% then 10% produces a 28% effective discount.
Other tools in shopping & discounts.
Normalize mixed package sizes and rank up to six products by unit price, including the gap to the next-best option.
Add tax, remove tax from a total, or infer an effective rate with state-average and custom-rate modes.
Normalize weekly, monthly, quarterly, and yearly bills, separate active from paused items, and surface the largest review opportunity.