Customer churn: formula, example and how to reduce it
Churn is the share of customers or revenue lost over a period due to cancellations, non-renewals, contract terminations, or inactivity. It is a key indicator of customer base health that affects Retention/LTV, growth rate, and acquisition economics (CAC payback).
What the Metric Measures
The loss of customers (logo churn) or recurring revenue (revenue churn) over a period. Distinguish between voluntary churn (dissatisfaction, price, competitors) and involuntary churn (payment failures, delinquencies), as well as gross and net figures (accounting for upsells/cross-sells).
Calculation
- Customer Churn, % = Customers lost / Customer base at start of period × 100
(alternative: average base: (start+end)/2) - Gross Revenue Churn, % = (MRR lost to churn + contraction) / MRR at start × 100
- Net Revenue Retention (NRR), % = (MRR at start − churn − contraction + expansion) / MRR at start × 100
- Gross Revenue Retention (GRR), % = (MRR at start − churn − contraction) / MRR at start × 100
- Involuntary Churn, % is the share of losses due to payment failures
Exclude new customers and reactivations from the base when calculating churn; count only paid and active subscriptions/contracts; fix the frequency (monthly/quarterly) and currency for MRR/ARR.
Calculation example
There were 2,000 active customers at the start of the month and 70 of them cancelled or stopped buying during it. Churn = 70 / 2,000 × 100 = 3.5% a month, which means losing about 35% of the customer base in a year. If mostly small customers left, revenue churn may be only 1.5%.
Data Sources
CRM/billing/payment gateways (Stripe/WayForPay/etc.), subscription and contract databases, helpdesk (cancellation reasons), product analytics (activity), financial reporting (MRR/ARR).
Interpretation
- Churn↑ signals problems with service value/quality, pricing, onboarding, support, or competition
- NRR > 100% means upsells/expansion offset churn; GRR shows “baseline stickiness” without upsells
- High involuntary churn: set up payment retries, card updates, dunning, and alerts
- Correlate with NPS/CSAT, Retention, the share of active users, payment declines, and price/discounts
Useful Breakdowns
- Cohorts by month/acquisition channel; customer age/tenure
- Plan/tier/product; B2B/B2C/VIP segment; geography/language
- Cancellation reasons (price, functionality, service, competitors, budget)
- Voluntary vs involuntary; product activity; interactions with support
Dashboard Visualizations
- Trends of Customer/Revenue Churn and GRR/NRR
- Retention cohorts (survival curves) by acquisition month
- Pareto of cancellation reasons; churn heatmaps by plan/channel
- Funnel “onboarding → activation → habit → cancellation”
- Correlations with NPS/CSAT, activity, and price
How to Set Targets
Define benchmarks by business model (SaaS/e-commerce/services): GRR ≥ 85–95%, NRR ≥ 100–120% (for B2B SaaS). Plan initiatives: better onboarding, retention/loyalty programs, pricing packages, win-back, and reducing involuntary churn through retries/dunning/Token Billing.
Common Mistakes
- Mixing new customers, reactivations, and the existing base in the denominator
- Using an average without controlling for cohorts and tenure
- Counting revenue with VAT/one-time payments in MRR/ARR
- Ignoring the difference between voluntary and involuntary churn
- Not tracking cancellation reasons or working on them in a “closed loop”
Discussion Questions
- Which 3 reasons drive 80% of churn, and how can they be eliminated?
- How will churn change after improving onboarding/activation?
- Which pricing/discount strategy minimizes churn without sacrificing margin?
- What is the impact of retries/dunning on involuntary churn?