Digital Marketing KPIs That Matter, Stage by Stage (With Formulas)
Most marketing reports are too long. Thirty metrics, coloured arrows, and at the end of the meeting nobody can say whether marketing worked. A KPI is not just any number; it is a number that leads to a decision. Below are the ones worth tracking at each stage of the funnel, with formulas you can put straight into a spreadsheet.
| KPI | Funnel stage | Formula | Question it answers |
|---|---|---|---|
| CPM | Awareness | Cost ÷ impressions × 1,000 | What does attention cost? |
| CTR | Consideration | Clicks ÷ impressions × 100 | Does the ad make people act? |
| Conversion rate | Conversion | Conversions ÷ clicks × 100 | Does the page turn visits into results? |
| CPA | Conversion | Cost ÷ conversions | What does one result cost? |
| ROAS | Conversion | Ad revenue ÷ ad spend | Do ads return more than they cost? |
| CAC | Business | Acquisition cost ÷ new customers | What does a new customer cost? |
| LTV (simple) | Retention | AOV × lifetime orders × gross margin | What is a customer worth? |
| Payback period | Business | CAC ÷ monthly margin per customer | How fast does a customer pay back? |
Metric or KPI?
A metric is any number a platform can show you. A KPI is a key number tied to a goal. Every real KPI has four things: a formula, a target, an owner and a review rhythm. If one of the four is missing, it is a metric, and it belongs in the appendix, not on the first page. A practical rule: one owner per KPI. If two people own a number, nobody owns it.
Awareness: are the right people seeing us?
- Reach: the number of unique people who saw the ad.
- Frequency = impressions ÷ reach. Too low and nobody remembers; too high and people get annoyed.
- CPM = cost ÷ impressions × 1,000. The price of attention.
- Video completion rate = completed views ÷ video starts × 100.
- Branded search trend: how often people search for your brand name over time. A slow but honest signal that awareness is building.
The decision at this stage: is the message reaching enough of the right people, often enough, at a reasonable price?
Consideration: is anyone interested?
- CTR = clicks ÷ impressions × 100.
- CPC = cost ÷ clicks.
- Engagement rate on the site: the share of visits in which people actually interact with the page. In Google Analytics 4 this is the engagement rate, based on "engaged sessions".
- Cost per conversation: where sales start in Instagram messages or WhatsApp, this matters more than likes.
- Saves, shares and profile visits: stronger signals of interest than likes.
The decision: are the message and the landing page interesting enough to move people forward?
Conversion: are we getting business?
- Conversion rate (CVR) = conversions ÷ clicks (or sessions) × 100.
- CPA = cost ÷ conversions.
- Cost per qualified lead and lead-to-sale rate = sales ÷ leads × 100. For B2B, these two matter more than the plain cost per lead.
- ROAS = revenue from ads ÷ ad spend.
- Break-even ROAS = 1 ÷ gross margin. Any ROAS below this line loses money on the first order.
- Average order value (AOV) = revenue ÷ number of orders.
The decision: is the cost of a sale acceptable compared with what a sale earns?
Retention: do customers come back?
- Repeat purchase rate = customers with two or more orders ÷ all customers × 100.
- Churn rate = customers lost in the period ÷ customers at the start of the period × 100.
- Customer lifetime value (LTV), simple version = average order value × number of orders per customer over their lifetime × gross margin.
- Email and messaging: click rate and unsubscribe rate. Do not rely on open rate. Since Apple introduced Mail Privacy Protection in 2021, many opens are recorded automatically, so the number is inflated.
The decision: is your customer base growing in value, or are you refilling a leaking bucket?
Business level: does marketing pay?
- CAC = total acquisition cost (media, agency, tools, team) ÷ new customers.
- LTV:CAC: how many times a customer's lifetime margin covers the cost of acquiring them. A ratio close to 1 means you are buying customers for roughly what they are worth, with nothing left for overheads or profit.
- Payback period = CAC ÷ monthly gross margin per customer. The number of months until a customer pays back what it cost to win them.
- MER = total revenue ÷ total marketing spend. Simple, blended and hard to manipulate with attribution settings.
These are the numbers your CEO and finance team care about. Put them first.
How to build a one-page KPI report
- Top line: business KPIs such as revenue, new customers, CAC and MER.
- Below: one or two KPIs per funnel stage, no more.
- Compare each number with its target and with the same period last year, not only with last month. Seasonality distorts month-on-month comparisons.
- Comment in three lines: what happened, why, and what you will do next.
- Separate sources: show platform-reported numbers and CRM or sales numbers side by side, clearly labelled.
Numbers to stop treating as KPIs
- Follower count on its own. It does not pay salaries.
- Likes. The cheapest signal there is.
- Impressions without reach and frequency. They hide whether you reached many people once or a few people many times.
- Platform ROAS on its own. Every platform grades its own homework.
- Email open rate, for the reason above.
The takeaway
Next to every number in your report, write the decision it informs. Delete every number that informs none. What remains is your KPI set, usually far shorter and far more useful than the report you started with.
