Monthly Churn Rate: The Silent Growth Killer
Churn rate measures the percentage of customers or revenue lost each month. Even small differences compound dramatically over time.
| Model | Seed | Series A | Series B | Top quartile |
|---|---|---|---|---|
| B2B SaaS | 3-7% | 2-5% | 1-3% | <3% |
| Consumer | 5-10% | 3-7% | 2-5% | <5% |
Monthly churn rate is the percentage of customers (logo churn) or revenue (revenue churn) lost in a given month. It's the gravitational force working against your growth — and small differences in churn compound into massive differences in outcomes over time.
What It Is
Logo Churn Rate = (Customers lost this month / Customers at start of month) x 100. Revenue Churn Rate = (MRR lost from churned and contracted customers / MRR at start of month) x 100. Track both — a company can have low logo churn but high revenue churn if its biggest customers are leaving.
Why It Matters
The math of churn is brutal. At 5% monthly churn, you lose 46% of your customers annually. At 2%, you lose 21%. Over three years, a company with 2% monthly churn retains 48% of a cohort while a company with 5% monthly churn retains just 16%. That 3-percentage-point difference means three times more retained customers. Every improvement in churn compounds across your entire customer base for every future month.
How to Calculate It
Calculate churn over a consistent time window. Exclude customers acquired within the period to avoid mixing acquisition and retention metrics. Segment by plan size, customer type, and acquisition channel. The aggregate number hides important patterns — your SMB segment might churn at 8% while enterprise churns at 1%, and the blended rate tells you nothing useful.
Startup Anecdote
Baremetrics, the SaaS analytics company, publicly shared their churn struggles as part of their "open startup" philosophy. At one point, their monthly churn hit 7-8%, meaning they had to replace nearly their entire customer base every year just to stay flat. Founder Josh Pigford documented their multi-year fight to reduce churn: they rebuilt onboarding, added proactive health scoring, introduced annual plans (which dropped churn for that segment by 60%), and personally called every churning customer. It took over two years, but they got monthly churn below 4% — and the business finally became sustainably profitable.
Key Takeaway
Churn is not a single problem — it's a symptom of multiple issues. Segment your churn data to find the root causes. Common buckets: poor onboarding (churn in first 30 days), missing features (churn at 3-6 months), lack of organizational buy-in (churn at contract renewal). Attack the largest bucket first, and treat any monthly churn above 3% in B2B or 5% in B2C as a critical issue to resolve before scaling.