CPA and ROAS are the two most important metrics for knowing whether your Google Ads is profitable. This guide explains what they are, how to set realistic targets, and what makes a target achievable or not.
CPA — Cost Per Acquisition
CPA is how much it costs you to get one conversion. If you spend €200 and get 4 sales, your CPA is €50.
A "good" CPA depends entirely on your business. €80 may be excellent for a dental clinic, too expensive for a €20 accessories shop, and a bargain for a law firm.
CPA ranges by industry (reference)
- E-commerce retail — €8–60 (depends on average order value)
- Legal services — €80–500+ (very competitive sector)
- Healthcare / clinics — €20–150 per appointment or contact
- B2B SaaS — €30–300 per trial or demo
- Finance / insurance — €60–400 per lead
- Local services — €15–120 per call or visit
- Education — €25–150 per enrollment inquiry
These are averages. Your actual CPA may be outside these ranges for many reasons (landing page, competition, budget, product). AdPredictor uses them as a reference to calibrate your goals, not as absolute truth.
ROAS — Return On Ad Spend
ROAS = Revenue generated / Ad spend. A ROAS of 4x means for every €1 spent on ads, you generate €4 in sales.
The minimum profitable ROAS depends on your margin:
- 25% margin → you need ROAS ≥ 4x to break even on ads
- 40% margin → you need ROAS ≥ 2.5x
- 60% margin → you need ROAS ≥ 1.7x
Formula: Minimum ROAS = 1 / margin. If your margin is 30% (0.30), the minimum break-even ROAS is 1/0.30 = 3.3x.
Why your target may be unachievable
Several factors create a CPA "floor" that no amount of optimisation can break through:
- Industry CPC — if average CPC is €5 and your conversion rate is 2%, the minimum CPA is mathematically €250
- Insufficient budget — with less than €30/day smart bidding has insufficient data and CPA is 20–40% higher than optimal
- Landing page — a page with 0.5% conversion rate (vs 3% average) multiplies CPA by 6, regardless of the campaign
- Product price — if your product is €30 and your CPA target is €25, each sale loses money on direct costs
- Competition — more competitors = higher CPCs = higher CPA floor
How AdPredictor uses this data
When you set your CPA or ROAS target, the AI:
- Compares your target against benchmarks for your industry and conversion type
- Checks that your CPA target doesn't exceed your average order value (if you've entered it)
- In chat, always works toward your goal but tells you honestly when something is unachievable and why
- Gives a concrete roadmap (quick wins in 1-2 weeks, structural improvements in 1-3 months) to approach your target