Margin Guardrails

Free Shopify profit & break-even calculator

See what you really make on each sale after product cost, payment fees, shipping, returns and discounts, plus the lowest price and deepest discount you can afford.

Your product
Costs of each sale
You make $6.17 per sale (19.3% margin), below your 20% target.
Break-even price
$25.30
Price for a 20% margin
$32.32
Deepest discount before a loss
36%
Deepest discount at your target
19%
Price paid (after 20% off)$32.00
− Product cost$18.00
− Payment fees$1.23
− Shipping you pay$5.00
− Returns allowance$1.60
= Profit per sale$6.17

Check every product in your store automatically

Margin Guardrails runs this for every product using your real costs and the prices customers actually paid, forecasts the next 30 days and tells you how to fix each product that loses money.

Get Margin Guardrails on the Shopify App Store

How the calculator works

Profit per sale = price the customer pays − product cost − payment fees (percentage + fixed fee) − shipping you pay − an allowance for revenue lost to returns.

Break-even price is the lowest price at which a sale doesn't lose money once all of those costs are covered. The deepest discount before a loss is how far you can discount from your current price before each sale starts losing money.

Why discounts matter so much

Fees and returns shrink with the price, but your product cost and shipping don't. A product with a healthy margin at full price can lose money on every sale during a promotion. Try raising the discount above to see where your break-even point is.

What isn't included

  • Ad spend. If you advertise a product, subtract your ad cost per sale too.
  • Taxes, and fixed costs like rent, staff, apps and subscriptions.