Metrics that get mixed up
Side-by-side comparisons, each with a shared calculator.
Four pairs of metrics that are easy to mix up: CPI, CPA and CAC; ARPU and ARPPU; LTV and ROAS; DAU/MAU and retention. Each page sets the formulas side by side and runs both in one calculator.
Which comparison do you need?
- CPI vs CAC vs CPAThree cost metrics that are often mixed up. Each prices a different step of the funnel, from the install to the paying customer.
- ARPU vs ARPPUTwo revenue-per-user metrics that differ only in who you divide by, and that can move in opposite directions.
- LTV vs ROASLifetime value looks forward at what a user is worth; ROAS looks back at what a campaign has earned so far. Read together, they tell you when spend pays back.
- DAU/MAU vs retention rateTwo engagement measures that sound alike and answer different questions: how often active users come back, and how many new users stay at all.
Questions
Why are these metrics so often confused?
Because they share a shape: each is a cost or revenue divided by a count of users. The difference is which users are counted and over what time, which is exactly what each comparison sets out.
What is the difference between a metric and a KPI?
A metric is any measured quantity; a KPI is a metric a team has chosen as a target for judging performance. Most metrics here become KPIs only for the teams whose work moves them.
Do I need an MMP to measure these metrics?
Not for all of them. Engagement and monetisation metrics come from product analytics and billing data, while metrics split by ad channel, such as CPI, ROAS or retention by source, need installs attributed to campaigns.
Are the calculator's example inputs benchmarks?
No. The example inputs only make the calculator show a worked answer when the page loads; they are not typical, good or target values. Replace them with your own numbers.
Does the calculator send my numbers anywhere?
No. It runs entirely in your browser, and nothing you type is stored or sent anywhere.