Editorial principles
Transparent arithmetic before performance claims
Keep ROAS and profit separate
Attributed revenue efficiency is never labelled net profit or total business ROI.
Show the cost boundary
Margin-based outputs state that fixed and unentered costs remain outside the result.
Avoid universal benchmarks
The site does not assign generic poor, good, or excellent ROAS bands.
Expose substituted formulas
The calculator shows the user's values inside the arithmetic so the result can be checked.
Core formulas
What each output calculates
ROAS
Attributed revenue ÷ ad spendDisplayed as a multiple and percentage. A 4.00× ROAS is also 400%.
Required attributed revenue
Ad spend × target ROASA planning target only. The result is not a forecast or guarantee.
Contribution margin from cost rates
1 − COGS rate − fulfilment rate − fee rate − refund rateAll rates are proportions of the same revenue base. The form rejects totals at or above 100%.
Break-even ROAS
1 ÷ contribution margin before adsThe threshold covers ad spend within the entered contribution boundary, not every business cost.
Estimated contribution after ads
Attributed revenue × contribution margin − ad spendFixed overhead, salaries, tax, financing, and other unentered costs are excluded.
Contribution return
Estimated contribution after ads ÷ ad spendA scoped operating measure used by this calculator; it is not presented as total business ROI.
CPA
Ad spend ÷ attributed actionsThe action must be defined consistently, such as a purchase, lead, or sign-up.
Paid-media CAC
Ad spend ÷ new customersMedia-only acquisition cost, not full customer acquisition cost.
Validation
Input and rounding rules
| Input or output | Rule | Reason |
|---|---|---|
| Ad spend | Must be greater than zero. | Prevents division by zero or an infinite ROAS. |
| Attributed revenue | Must be zero or greater. | Supports a zero-revenue campaign without accepting negative revenue. |
| Target ROAS | Must be greater than zero. | Keeps the target-revenue calculation meaningful. |
| Contribution margin | Greater than 0% and no more than 100%. | A zero or negative margin has no finite positive break-even ROAS in this model. |
| Detailed cost rates | Every field required; each 0–100%; total below 100%. | Prevents blank values from silently becoming zero and avoids non-positive derived margin. |
| Currency | Formatting only; no exchange-rate conversion. | All inputs must already use the same currency. |
| Display rounding | Money uses the selected currency; ratios and percentages use up to two decimals. | Calculations retain JavaScript numeric precision before display formatting. |
| Break-even status | Amounts within half a currency cent are treated as equal. | Avoids a false above/below label caused only by floating-point fractions smaller than displayed currency precision. |
Attribution boundary
Reported revenue is not automatically incremental revenue
Advertising platforms can use different conversion events, lookback windows, attribution models, and view-through rules. The calculator accepts the attributed value you enter; it does not verify causal lift or reconcile duplicated credit across platforms.
For a fair comparison, use the same event, reporting dates, attribution window, and as similar an attribution scope as practical. Avoid adding platform-reported values together without checking for overlapping credit.
Source: Google Ads platform-comparable conversion methodology.
Calculator data
Browser-side processing
The launch calculator has no account, upload, database, advertising tag, or analytics tag. Calculator values are processed by client-side code in the browser and are not intentionally submitted or stored by this site. The copy button writes a text summary to the browser clipboard only after the user selects it.
Cloudflare hosts and delivers the static files and may process ordinary technical request data as part of that service. See the site's Privacy page and Cloudflare privacy policy.
Primary sources
Terminology and formula basis
- Google Ads glossaryROAS, ROI, conversion, conversion value, and CPA definitions.
- Google Ads: About return on investmentProfit-based ROI framing and example cost boundary.
- Amazon Ads MathNo universal good-ROAS threshold; margin context; ROAS and break-even formulas.
- Google Ads: Platform-comparable conversionsAttribution scope, view-through conversions, and comparison cautions.
Competitor pages and Google result screenshots informed interaction expectations and query intent only. Their wording, code, layouts, images, ratings, creator profiles, and benchmark claims were not copied or used as factual sources.