SaaS metrics lists keep growing because every function added its favorites: marketing brought funnel metrics, sales brought pipeline metrics, finance brought efficiency ratios. A founder who tries to track all of them tracks none of them well. You need twelve, and more usefully, you need them grouped by the question each answers.
Revenue: how much, and how reliably?
1. MRR (monthly recurring revenue). The sum of all active subscriptions normalized to a month. The heartbeat number; everything else derives from it. Full guide.
2. ARR (annual recurring revenue). MRR x 12. Same information at investor zoom; use it for the outside world, run the company on MRR. Full guide, and when to use which.
3. Net new MRR. New + expansion - contraction - churned MRR, the four movements that explain why revenue changed. A flat headline MRR can hide healthy acquisition cancelled out by churn; the movements cannot.
4. ARPA (average revenue per account). MRR divided by active customers. Rising ARPA means you are moving upmarket or expanding accounts; falling ARPA with rising customer count means you are buying volume with discounts.
Retention: does the bucket leak?
5. Revenue churn rate. Churned MRR this month divided by MRR at the start of the month. The single most consequential percentage in the business: at 5% monthly churn, half your revenue base disappears every 14 months and growth has to outrun the leak. The churn rate calculator shows customer and revenue churn side by side.
6. Net revenue retention (NRR). Revenue from an existing cohort today versus a year ago, including expansions and churn. Above 100% means the product grows without new sales, the strongest signal a SaaS business can show. Its sibling, the SaaS quick ratio, divides everything gained by everything lost and answers the same question from the growth side.
7. Customer concentration. Your largest customer's share of MRR. Not on most lists, which is exactly why concentration disasters keep surprising founders. Above 20% deserves a plan; here is why.
Efficiency: what does growth cost?
8. CAC (customer acquisition cost). All sales and marketing spend in a period divided by customers acquired in it. Count salaries, not just ad spend, or the number flatters you. The CAC calculator includes the payback period.
9. LTV to CAC. Lifetime value (ARPA x gross margin / churn rate) against acquisition cost. The classic threshold is 3:1; below that, growth spends more than customers return. The LTV calculator computes the ratio from your churn and margin.
10. Burn multiple. Net burn divided by net new ARR: how many euros you burn to add one euro of recurring revenue. Investors increasingly quote this before anything else; formula and benchmarks.
Past Series A, two more efficiency ratios join the vocabulary: the SaaS magic number, which judges the sales and marketing spend on its own, and the Rule of 40, which folds growth and margin into one score — the full treatment, including the ways companies flatter themselves with it, has its own post. Both are recombinations of numbers already on this list, which is rather the point of keeping the list short.
Survival: how long can you keep playing?
11. Net burn. Monthly spending minus monthly cash revenue, the rate the bank account drains. What counts and what does not.
12. Runway. Cash divided by net burn, expressed as a date, not a number of months. Dates create urgency that "14 months" does not. Find your date.
SaaS metrics cheat sheet
The twelve metrics and their formulas on one card, in the order they appear above:
| Metric | Formula |
|---|---|
| MRR | sum of active subscriptions, normalized to a month |
| ARR | MRR x 12 |
| Net new MRR | new + expansion - contraction - churned |
| ARPA | MRR / active customers |
| Revenue churn | churned MRR / starting MRR |
| NRR | cohort MRR today / cohort MRR a year ago |
| Customer concentration | largest customer's MRR / total MRR |
| CAC | sales + marketing spend / new customers |
| LTV to CAC | (ARPA x gross margin / churn rate) / CAC |
| Burn multiple | net burn / net new ARR |
| Net burn | monthly spending - monthly cash revenue |
| Runway | cash / net burn |
What counts as a good value for each is a separate question, and the accepted ranges are collected in the benchmark tables, each with its source and a link to the full definition.
The stage rule
You do not need all twelve on day one. Pre-revenue, only 11 and 12 exist. Early revenue, add the MRR family and churn. Past product-market fit, efficiency metrics start deciding your next round. Whatever the stage, the set fits on one screen, which is the actual test of a metrics setup: if checking your numbers takes more than a minute, you will stop checking. Plainhub keeps the survival and revenue metrics live from what you record; the efficiency ratios fall out of the same numbers at the end of each month.
Twelve numbers, four questions: how much comes in, does it stay, what does growth cost, and how long can you play. Every 40-metric dashboard is these four questions wearing costumes.