Ecommerce advertising calculator
Break-even & Target ROAS Calculator
Find the minimum ROAS that protects your cash and the target ROAS that leaves the profit you actually want.
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Results
Your profitability guardrails
Example values are shown until you calculate with your own numbers.
Target ROAS 3.12× · 311.5%
Your target is mathematically reachable with the costs entered.
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Your numbers stay on this device
All calculations run in your browser. Input values are not sent to 321Kit and are not stored in an account.
Method
How the calculator works
The calculator starts with contribution margin, then works backward to the advertising spend your business can afford.
1. Contribution margin before ads
We subtract product cost, fulfillment, allocated overhead and revenue-based fees from average order value.
Contribution margin = (AOV − all costs before ads) ÷ AOV 2. Break-even ROAS
At break-even, every dollar of contribution profit can fund advertising and profit after ads is zero.
Break-even ROAS = paid revenue share ÷ contribution margin 3. Target ROAS and maximum CPA
Your profit goal reserves part of the contribution margin. The remainder is the maximum advertising budget.
Target ROAS = paid revenue share ÷ (contribution margin − target profit margin) What does paid revenue share change?
At 100%, the result is a product-level threshold. Below 100%, the model assumes contribution from non-paid revenue can support acquisition spend. Use that blended view only when it matches how you manage the whole business.
How are returns modeled?
The return allowance is an editable percentage of gross revenue. Use your own observed loss rate; the calculator does not insert an industry benchmark.
FAQ
ROAS calculator FAQ
What is break-even ROAS?
Break-even ROAS is the revenue-to-ad-spend ratio where contribution profit exactly covers advertising. Below it, the modeled order loses money after ads; above it, money remains.
Why is target ROAS higher than break-even ROAS?
Break-even reserves no profit after advertising. Target ROAS protects the profit margin you entered, so advertising must consume a smaller share of revenue.
Should fixed costs be included?
Use the allocated fixed-cost field when you want each order to help cover overhead. Enter 0 when you only want a variable contribution-margin view. Keep the method consistent when comparing products.
Is ROAS the same as profit?
No. ROAS compares attributed revenue with ad spend and ignores product economics by itself. Profit depends on COGS, fulfillment, fees, returns, overhead and advertising together.
Does changing currency convert my numbers?
No. Currency selection only changes symbols and number formatting. Enter every monetary amount in the same currency.
How do I calculate break-even ROAS for eMAG, Amazon or another marketplace?
Enter the marketplace commission under payment and platform fees, then add your product cost, fulfillment and return allowance. The calculator uses your actual rates instead of a platform default that may be outdated.
Does 321Kit upload my financial data?
No. The calculation runs locally in your browser. 321Kit records only a minimal anonymous completion event and a coarse source category, never the values you enter.