Churn

Churn measures customers leaving — the inverse of retention. It's the single most important driver of LTV, unit economics, and long-term SaaS valuations.

Churn rate formula

Churn rate = Customers lost in period / Customers at start of period

Two variants matter and should always be reported together:

The two diverge because not all customers are equal-revenue. Losing one $50k/yr customer matters more than losing twenty $100/yr customers, even though customer-churn % might be lower in the first case. Most boards track revenue churn as the primary metric; customer churn as a leading signal.

Churn calculator: worked example

A SaaS company starts the month with 1,000 customers, each paying an average of $100/mo (total MRR = $100k).

During the month, 40 customers cancel, including 2 enterprise accounts that contributed $5,000/mo combined.

• Customer churn = 40 / 1,000 = 4.0%
• Revenue churn = (40 × $100 average − but actually $13k including enterprise losses) / $100,000 = 13.0%

Wait — that doesn't compute. Let's be precise: 38 customers at $100/mo lost = $3,800. 2 enterprise customers at $2,500/mo each = $5,000. Total revenue lost = $8,800.

• Revenue churn = $8,800 / $100,000 = 8.8%

Customer churn (4%) understated the problem; revenue churn (8.8%) tells the real story.

SaaS churn benchmarks

For enterprise, report annual gross + net dollar churn. For SMB and consumer, report monthly.

Voluntary vs involuntary churn

For consumer SaaS, involuntary churn can be 30–50% of total churn. Companies that conflate the two will mis-attribute their churn problem and try to fix product/positioning when the actual fix is payment infrastructure.

Why churn dominates LTV

Churn appears in the denominator of customer lifetime: lifetime ≈ 1/churn. A 5% monthly churn → 20-month lifetime. A 2% monthly churn → 50-month lifetime. Halving churn more than doubles LTV.

This is why "improve retention" is the highest-leverage growth strategy for most subscription businesses — moving churn from 5% to 4% increases LTV by ~25% with no change in acquisition cost.

How to reduce churn

In order of leverage:

1. Fix involuntary churn first — dunning, card-update flows, payment retries. Often a 1–2 month implementation that recovers 20–40% of total churn.
2. Identify the high-churn segment — cohort by acquisition channel, ICP fit, contract size. Stop acquiring the segment that churns above your average.
3. Improve activation — the customers most likely to churn are those who never reached the "aha moment." Better onboarding moves activation rate up and lifetime churn down.
4. Annual contracts where possible — switches monthly churn from a continuous problem to a renewal-cycle problem; smooths cash flow.
5. Account-management touch for enterprise — quarterly business reviews, executive sponsorship, success plans. Operationally expensive but yields the lowest churn segments.

Common churn mistakes

Related

• Retention — the inverse of churn; same data, different framing
• LTV — driven primarily by churn
• NRR — net revenue retention; expansion can offset churn
• Cohort Analysis — the right way to measure churn
• Product-Market Fit — PMF shows up as a churn curve that flattens