One snapshot, every core KPI
Paid media reporting keeps coming back to the same handful of ratios. Enter spend, impressions, clicks, and conversions from any campaign — plus revenue if you have it — and the calculator derives every standard KPI at once, so you don’t have to rebuild the same spreadsheet formulas for each report.
The formulas
| KPI | Formula | What it tells you |
|---|---|---|
| CTR | clicks ÷ impressions × 100 | How compelling the ad is to the audience seeing it |
| CPC | spend ÷ clicks | What you pay for each visit |
| CPM | spend ÷ impressions × 1000 | What you pay for reach, per thousand impressions |
| Conversion rate | conversions ÷ clicks × 100 | How well the landing page and offer convert traffic |
| CPA | spend ÷ conversions | What each conversion costs |
| ROAS | revenue ÷ spend | Revenue returned per unit of spend |
| AOV | revenue ÷ conversions | Average value of each conversion |
| Revenue per click | revenue ÷ clicks | What each visit is worth |
A worked example
Spend $2,500 on 180,000 impressions, getting 5,400 clicks and 243 conversions on $12,000 revenue:
- CTR = 5,400 ÷ 180,000 = 3.0%
- CPC = 2,500 ÷ 5,400 = $0.46
- CPM = 2,500 ÷ 180,000 × 1,000 = $13.89
- Conversion rate = 243 ÷ 5,400 = 4.5%
- CPA = 2,500 ÷ 243 = $10.29
- ROAS = 12,000 ÷ 2,500 = 4.8
Reading the numbers together
Each KPI in isolation can mislead; pairs tell the story. A great CTR with a poor conversion rate means the ad over-promises or the landing page under-delivers. A low CPC with a high CPA means cheap clicks that don’t convert — often a targeting problem. ROAS without margin context says nothing about profit: a ROAS of 3 is excellent at 60% gross margin and a loss at 25%.
Frequently asked questions
What’s a good CTR / CPA / ROAS?
It depends so heavily on industry, channel, and placement that universal benchmarks mislead more than they help. Search ads routinely see CTRs several times higher than display; CPA tolerances depend entirely on what a customer is worth to you. The more useful comparison is your own campaign over time, and against your other channels.
What’s the difference between ROAS and ROI?
ROAS compares revenue to ad spend only (revenue ÷ spend). ROI compares profit to total cost, including product costs, fees, and labour. A campaign can have a healthy ROAS and a negative ROI if margins are thin — work out your break-even ROAS as 1 ÷ gross margin (at a 40% margin, break-even ROAS is 2.5).
Should conversion rate be measured against clicks or impressions?
Against clicks (or sessions) — that’s the standard and what this calculator uses. Conversions per impression mixes ad performance and landing-page performance into one opaque number; CTR and conversion rate keep them separate, which is what lets you diagnose where the problem is.
My platform reports different numbers than this calculator. Why?
Platforms apply their own attribution windows, conversion deduplication, and click filtering before reporting. This calculator does the plain arithmetic on whatever inputs you give it — which is exactly what you want for comparing channels on equal footing.