How to use
- Results → all metrics: enter the ad spend, impressions, clicks, conversions and revenue from your campaign report to get CPM, CPC, CTR, conversion rate, CPA and ROAS at once. Leave a field empty if you don’t have it — only the metrics that need it are skipped.
- Solve for one value: pick a metric (CPM, CPC, CTR, CPA or ROAS) and choose which of its three values to find. For example, get the budget for a target CPM and impression count, or the maximum spend for a revenue goal at a target ROAS.
Formulas
| Metric | Meaning | Formula |
|---|---|---|
| CPM | Cost per 1,000 impressions | spend ÷ impressions × 1,000 |
| CPC | Cost per click | spend ÷ clicks |
| CTR | Click-through rate | clicks ÷ impressions × 100 |
| Conversion rate | Conversions per click | conversions ÷ clicks × 100 |
| CPA | Cost per acquisition | spend ÷ conversions |
| ROAS | Return on ad spend | revenue ÷ spend × 100 |
The metrics chain together: CPC = CPM ÷ (CTR × 10) and CPA = CPC ÷ (conversion rate ÷ 100). At the same CPM, a better click-through or conversion rate lowers what you pay per click and per sale.
Example
A campaign spends 2,000 for 400,000 impressions, 4,000 clicks, 80 sales and 8,000 in revenue:
| Metric | Result |
|---|---|
| CPM | 5.00 |
| CPC | 0.50 |
| CTR | 1% |
| Conversion rate | 2% |
| CPA | 25.00 |
| ROAS | 400% (4×) |
Solving the other way: 1,000,000 impressions at an 8.00 CPM need a budget of 8,000, and a 10,000 revenue goal at 400% ROAS allows up to 2,500 in spend.
Things to keep in mind
- Results are for reference only. Each platform counts impressions, clicks and conversions differently and uses its own attribution window.
- A ROAS above 100% does not mean the ads are profitable. With a 25% profit margin, you need a ROAS of at least 1 ÷ 0.25 = 400% just to cover the ad spend. Check your margin with the margin calculator.
- Make sure spend figures are on the same basis (with or without tax and agency fees) before comparing campaigns.
- To plan sales targets that also cover fixed costs, use the break-even calculator.
FAQ
Is 400% ROAS the same as a ROAS of 4?
Yes — both mean 4 in revenue for every 1 spent. Some platforms show a percentage, others a ratio.
What does the “M” in CPM stand for?
Mille, Latin for thousand. CPM is the cost per thousand impressions.
Is anything I enter saved or sent anywhere?
No. All calculations run in your browser.