Discount Calculator — Check Profit Before a Sale

A discount reduces revenue faster than costs

When you reduce a product price, product cost, packaging and seller-paid shipping usually stay the same. Percentage fees shrink slightly, but most of the discount comes out of your contribution. A modest price reduction can therefore create a much larger percentage reduction in profit.

A worked promotion

Using the example product at $30, your contribution is $10.93 per order. A 20% discount lowers the selling price to $24. With the same costs and 10.9% percentage fees, contribution becomes $5.584, displayed as $5.58. That promotion removes almost half of the contribution even though the sticker price falls by only one fifth.

How many extra orders would you need?

Divide original contribution by discounted contribution, then subtract one and multiply by 100. In the example, approximately 95.7% more orders are needed to maintain the same total contribution. This assumes every extra order has the same costs, advertising expense does not increase, and enough customers want the promotion.

Find your discount limit

The largest discount before a per-order loss comes from your minimum sustainable price: all fixed per-order costs divided by one minus the percentage fee rate. This threshold only covers entered unit costs. It leaves nothing toward monthly overhead, returns or tax. If the original price already makes a loss, there is no safe discount under these assumptions.

Frequently asked questions