Churn Rate Calculator

Churn is the leak in the bucket: the share of customers you lose per period. Compute it, see the retention flip side, the implied customer lifetime — and what a monthly rate compounds to over a year.

Result

How to use this calculator

  1. Enter customers at the start of the period and how many were lost during it.
  2. Exclude new customers added during the period from both numbers.
  3. Pick monthly or annual — monthly view includes the compounding annual figure.

Formula used

Churn = Lost ÷ Starting customers × 100  ·  Lifetime = 1 ÷ churn

Keep new acquisitions out of the calculation — churn measures the leak, growth measures the tap. Monthly churn compounds: 3.5%/month is not 42%/year but 1 − 0.965¹² ≈ 34.8%. Revenue churn (MRR lost) can differ from customer churn when big accounts leave.

Example calculation

Worked example

42 of 1,200 customers lost in a month: churn = 3.5%, retention 96.5%, implied lifetime ≈ 28.6 months.

Compounded over a year that's 34.8% — of 1,000 customers today, only ~652 remain in 12 months without intervention.

Why churn dominates growth math

Churn caps growth invisibly: acquiring 5% new customers monthly while churning 3.5% nets 1.5% growth and a treadmill that speeds up with scale — the bigger you get, the more absolute customers each month's churn destroys. This is why retention improvements are worth multiples of equivalent acquisition wins: cutting churn from 3.5% to 2.5% extends average lifetime from 29 to 40 months, raising CLV ~40% across the entire base.

Watch cohorts, not just the blended rate: churn typically front-loads (early customers leave fastest), so a blended number mixes brand-new shaky cohorts with loyal veterans.

Why use this calculator?

Frequently asked questions

What is a good churn rate?

SMB-focused SaaS often runs 3–7% monthly; enterprise SaaS aims under 1% monthly (~10% annually); consumer subscriptions vary widely. Whatever the market, the direction of travel matters most.

Customer churn vs revenue churn — which matters?

Both: customer churn counts logos, revenue churn counts money. Losing many small accounts and one giant account can produce identical customer churn but very different revenue churn. Best-in-class SaaS reaches negative revenue churn — expansions outgrow losses.

How do I reduce churn?

Diagnose when and why people leave: onboarding gaps (churn in month 1–2), value gaps (usage decay before cancellation), or billing failures (involuntary churn, often 20–40% of the total and fixable with payment retries). Exit surveys and usage data beat guessing.

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