Setting a Google Ads budget without historical data is one of the challenges for beginner advertisers. A simulator allows estimating click volume, expected conversion numbers and cost per acquisition (CPA) based on sector and target keywords, even before launching the first campaign.
A Google Ads budget is built from several key metrics: average CPC (cost per click, varying by keyword and sector competitiveness), monthly search volume of target keywords, expected click-through rate (CTR) on ads, and website conversion rate. Basic formula: Monthly budget = Target clicks × Average CPC. To find break-even, maximum admissible CPA = conversion value × margin.
📐 Formula
Estimated clicks = Budget / Average CPC | Estimated conversions = Clicks × Conversion rate | CPA = Budget / Conversions
📊 Reference table
| Sector | Average CPC (US) | Average conversion rate | Average CPA |
|---|---|---|---|
| General e-commerce | $0.50–$2.00 | 2–4 % | $15–50 |
| Insurance / Finance | $10–$50 | 3–8 % | $100–500 |
| Legal / Attorney | $20–$80 | 2–5 % | $400–$1,500 |
| Real estate | $3–$15 | 1–3 % | $100–700 |
| Online education | $1.50–$8 | 3–8 % | $20–150 |
| Local services / Trades | $5–$25 | 8–20 % | $30–150 |
💡 Practical examples
Example 1: e-commerce with $500/month budget
Average CPC = $1.20. Clicks = 500 / 1.20 = 417 clicks/month. Conversion rate = 3%. Orders = 417 × 3% = 12.5. CPA = 500 / 12.5 = $40. If order value = $120, ROI = (120-40)/40 = 200%.
Example 2: find minimum budget for 10 leads/month
Sector: education. CPC = $3. Conversion rate = 5%. For 10 leads: clicks needed = 10 / 5% = 200. Budget = 200 × $3 = $600/month minimum.
Example 3: maximum CPA based on customer value
Average customer value = $500. Margin = 40% → $200 gross margin. Maximum profitable CPA = $200 × 50% (goal: keep 50% of margin) = $100. If current CPA = $130 → campaign unprofitable, improve conversion rate or reduce CPC.