A ROAS of 3 can be healthy for one business and insufficient for another. It shows the relationship between attributed revenue and ad spend. To know whether the numbers work, you also need margin, acquisition cost and revenue quality.
ROAS and CPA answer different questions
ROAS shows the revenue attributed to advertising for each real invested. CPA shows the cost of the action you chose to measure. That action may be a purchase, a lead or another goal; give it a clear name.
| Metric | Calculation | What to watch |
|---|---|---|
| ROAS | Attributed revenue ÷ ad spend | Revenue is not profit |
| CPA per sale | Ad spend ÷ attributed sales | Use confirmed sales |
| CPL | Ad spend ÷ received leads | A button click is not a received lead |
In an illustrative example, R$3,000 in ad spend and R$9,000 in revenue produce a ROAS of 3×, or 300%. With 15 sales, CPA per sale is R$200. The same spend with 60 leads yields a CPL of R$50. All three metrics coexist; none replaces the others.
Find your break-even ROAS using margin
Start with contribution margin before advertising: revenue minus variable costs linked to sales, such as delivery, supplies, taxes and fees. At a 40% margin, each R$100 in revenue leaves R$40 before ads and fixed costs.
With R$9,000 revenue and a 40% margin, R$3,600 remains before advertising. After R$3,000 in ads, R$600 remains. An apparently strong ROAS can leave little room for operations. If returns and discounts are not yet included, the revenue in the calculation also needs adjustment.
Turn the per-sale limit into a per-lead target
For businesses that sell after a conversation, the funnel does not end at the form. With average revenue of R$800, a 40% margin and a 20% lead closing rate, the break-even limit per lead is R$64: 800 × 0.40 × 0.20.
Do not adopt this as an automatic target. It does not reserve the contribution your business needs. Lower lead quality can also reduce closing rates. If the rate falls from 20% to 10%, the limit drops from R$64 to R$32 even with the same CPL.
- Separate received leads, qualified leads and confirmed sales.
- Use the closing rate of a cohort that has had time to move through your sales process.
- Do not mix repeat customers with new customers without stating the difference.
- Compare projections with actual results and record where assumptions failed.
Use projections to ask better questions
In the campaign calculator , change one assumption at a time. Observe the effect of improving the page, increasing closing rates or reducing CPC. This helps identify which stage needs investigation; it does not prove the improvement will happen.
A bidding target is different from a guaranteed result. Google describes target ROAS as guidance to optimize conversion value relative to cost. Before configuring it, check that reported values represent your economic goal. See the Google Ads target ROAS documentation .
Save assumptions with their date and source. In the next review, use the same revenue and conversion definitions. A good target becomes more useful when you can compare it with reality.