Coupon Profit Impact Calculator

About this calculator

A coupon that looks generous to customers can quietly erode a business’s margin far more than the discount percentage suggests, because the discount comes straight off revenue while the unit cost stays fixed. A 20% coupon on a product with a 40% margin, for instance, can cut profit per sale by half.

This calculator shows the profit and margin per sale after a coupon is applied, alongside how many margin points are given up compared to selling at full price. It’s a practical check for small business owners and e-commerce sellers deciding how deep a promotional discount can go, and for marketers weighing a coupon campaign’s expected volume lift against its real cost to the bottom line.