Work out the ROAS and CPA ceiling before you increase spend. Adjust the inputs below and use the result as a practical planning guardrail.
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ROAS
Adjust the inputs and use the output as a practical guardrail, not a black-box verdict.
Selected workbench
Work out the ROAS and CPA ceiling before you increase spend.
Spend guardrails
Break-even ROAS
1.90x
Revenue divided by maximum ad spend.
Max CPA before profit loss
$42.00
52.5% contribution margin
Variable costs
$38.00
Margin exists before ad spend.
Subtract every variable cost of one order from its value. What is left is the most you can spend on ads to win that order, your maximum CPA. Divide the order value by that amount to get break-even ROAS.
Break-even ROAS is the return on ad spend at which a sale covers its product, shipping, fee and other variable costs plus the ad cost, leaving zero profit. Below it each sale loses money. Above it each sale adds margin.
Divide the average order value by what is left after variable costs. A $100 order with $60 of variable costs leaves $40, so break-even ROAS is 100 divided by 40, or 2.5x, and the maximum CPA is $40.
Include every cost that rises with each order: product cost, shipping and fulfilment, payment and marketplace fees, and other per-order costs such as a returns allowance. Leave out fixed costs such as salaries and rent, which this calculator does not cover.
They describe the same limit in two ways. Maximum CPA is the most you can pay in ads for one sale before it loses money. Break-even ROAS is the order value divided by that amount.
Your variable costs are equal to or higher than the order value, so every sale loses money before any ad spend. Raise the price or lower the costs before you buy traffic.
Treat it as the floor. Break-even leaves zero profit, so set your target ROAS above it to cover fixed costs and the profit you want from each sale.
Save the audiences that matter, turn live signals into briefs, and keep reporting close to the decision that changed the campaign.