Product margin calculator
See the exact profit per unit after cost of goods, shipping, and fees — so you know which products are actually worth selling.
Enter your selling price, what you paid for the product, your shipping cost, and the fees your platform and payment processor take. The calculator shows gross profit per unit, your margin, and your markup on cost.
Product margin calculator inputs and results
How this calculator works
Platform and payment fees are calculated as a percentage of the selling price, then added to your fixed costs — cost of goods and shipping — to produce total per-unit cost. Gross profit is what's left after subtracting that total from your selling price.
Margin is gross profit expressed as a share of selling price. Markup is gross profit expressed as a share of cost of goods — useful when setting prices from a known unit cost. The two are related but not interchangeable: a 50% markup on cost produces a 33% margin, not 50%.
Want to know the maximum you can spend acquiring a customer through ads? Use the breakeven ad spend calculator.
About this tool
This calculator breaks down the per-unit economics of a physical product sold online. Inputs: selling price, cost of goods sold, shipping cost you absorb, platform or marketplace fee %, and payment processing fee %. Outputs: gross profit per unit, gross margin %, and markup % on cost of goods. Useful for pricing decisions and identifying which products are worth selling.
Frequently asked questions
What's the difference between margin and markup?
Margin is gross profit divided by selling price — the share of each sale you keep after costs. Markup is gross profit divided by cost of goods — how much you added on top of what you paid. A 50% markup produces a 33% margin, not 50%. Confusing the two is one of the most common pricing mistakes in ecommerce.
Should I include shipping in the cost or leave it out?
Include it if you absorb any part of it. Free shipping and flat-rate shipping that doesn't fully cover your carrier cost are both real costs of the sale. Ignoring them inflates apparent margin and makes products look more profitable than they are. If the customer pays shipping at cost, leave this field at zero.
What platform fee should I use?
Use the total percentage the platform takes from each sale. Amazon referral fees are typically 8–15% depending on category. eBay final value fees are 10–13%. Shopify's transaction fee is 0% if you use Shopify Payments, or 0.5–2% if you don't. Check your platform's current fee schedule — they change.
Why is my margin negative?
Your costs exceed your selling price, meaning you're losing money on every unit sold. The fastest fixes are raising the price, reducing cost of goods through better sourcing, or switching to a lower-fee platform. Shipping and platform fees are often larger than sellers expect when priced in individually.