Churn Rate

Churn rate measures the percentage of customers who leave your product or cancel their subscription during a given period. For subscription businesses, it is arguably the single most important metric because it determines whether your customer base is growing or shrinking underneath your acquisition efforts.

Why it matters: if you acquire 100 new customers per month but churn 80, your net growth is only 20. Reducing churn is almost always more impactful than increasing acquisition, because retained customers compound: they expand their usage, refer others, and cost nothing additional to acquire. A 5% monthly churn rate sounds small but means you lose nearly half your customers every year. A 2% monthly churn rate means you retain about 78% annually. That difference is transformative at scale.

How to calculate: customer churn rate = (customers lost during period / customers at start of period) x 100. Revenue churn rate = (MRR lost from cancellations and downgrades / MRR at start of period) x 100. Revenue churn can be negative if expansion revenue from existing customers exceeds losses, which is the gold standard for SaaS businesses and is called net negative churn.

Key distinctions: voluntary churn happens when customers actively cancel. Involuntary churn happens when payments fail (expired cards, insufficient funds). Involuntary churn can account for 20-40% of total churn in some businesses and is recoverable through dunning emails, card updaters, and retry logic. Tools like Stripe handle retry schedules automatically, and specialized tools like Baremetrics Recover or Churnkey focus on failed payment recovery.

Common mistakes: only measuring overall churn without segmenting by cohort, plan tier, or acquisition source. Your $29/month plan might churn at 8% while your enterprise plan churns at 1%, and the blended number hides both realities. Also, not distinguishing between logo churn (number of customers) and revenue churn (dollars lost), which can tell very different stories.

Practical example: a SaaS company with 5% monthly churn implements three changes: a 14-day "win-back" email sequence for at-risk users, in-app prompts when usage drops, and smart payment retries for failed charges. Over six months, churn drops to 3.2%, which at their scale saves $180K in annual recurring revenue.