The SaaS Metrics That Actually Matter (with Formulas)
Most SaaS founders track the wrong things first — signups, page views, social followers. The metrics that actually determine whether your business is healthy are about recurring revenue and the efficiency of your growth engine. Once you understand SaaS metrics properly, you will never look at a raw signup count the same way. Here's the complete set, with formulas.
Quick Answer
The SaaS metrics that matter are MRR/ARR (recurring revenue), churn (customers and revenue lost), LTV (customer lifetime value), CAC and CAC payback (cost and time to recover acquisition spend), and NRR (net revenue retention). Track recurring revenue and churn first — every other metric builds on them. Use the formulas below to compute each from your subscription data.
What "SaaS metrics" means
SaaS metrics quantify recurring revenue, retention, and how efficiently you acquire customers. Because revenue recurs, you measure the health of the base, not just one-off sales.
MRR and ARR
Monthly Recurring Revenue is the predictable revenue you bill each month; ARR is MRR x 12. Track new, expansion, contraction, and churned MRR to see what moves the total.
Churn
Logo churn is customers lost; revenue churn is recurring revenue lost. Revenue churn matters more because losing one big account can outweigh several small ones.
LTV, CAC, and NRR
LTV estimates the total revenue a customer brings over their lifetime. CAC is what you spend to acquire one customer, and CAC payback is how many months of margin it takes to earn that back. NRR measures revenue retained (plus expansion) from existing customers.
Formula table
Metric | Formula |
|---|---|
MRR | Sum of monthly recurring revenue across active subscriptions |
ARR | MRR x 12 |
Revenue churn | Recurring revenue lost in period / recurring revenue at start |
LTV | Average revenue per account / churn rate (gross-margin adjusted) |
CAC | Total sales + marketing spend / new customers acquired |
CAC payback | CAC / (monthly gross margin per customer) |
NRR | (Start MRR + expansion - contraction - churn) / Start MRR |
How this maps to FastStaq
These metrics are computed from your subscription data. FastStaq's Stripe integration with webhook-synced subscription records gives you the raw events — new subscriptions, upgrades, cancellations — that feed MRR, churn, and NRR. The boilerplate stores the data; you compute the metrics on top. See the SaaS billing guide and customer acquisition cost.
Frequently asked questions
Which metric should I track first? MRR and churn — they describe the health of your recurring base and feed everything else.
Is logo churn or revenue churn more important? Revenue churn — it accounts for the size of the accounts you keep or lose.
What is a good NRR? Above 100% means existing customers grow your revenue even before new sales; many strong SaaS aim well above that.
Next steps
Back to the SaaS billing guide
