Churn & Retention Rate Calculator
Enter your starting customer count, customers lost, and — optionally — your starting MRR, lost MRR, and expansion MRR. The calculator instantly computes both customer churn (headcount-based) and revenue churn (dollar-based), converts monthly rates to annual via compounding rather than ×12, derives implied average customer lifetime, and flags your result against three SaaS benchmark bands. The distinction between customer churn and revenue churn is the main surface: they often diverge sharply, and reading the wrong one leads to badly misjudged retention strategy.
MRR inputs (optional — for revenue churn & NRR)
Customer churn rate
5.00% /mo
Retention 95.00% · Annual 45.96%(compounded, not ×12)
Avg customer lifetime
20.0 mo
= 1 ÷ monthly rate
Elevated — warning zone
Customer churn 3–5%/mo — investigate retention immediately.
Customer churn vs benchmarks
Bars: customer churn · 1% · 3% · 5% benchmarks
SaaS benchmark comparison
| Band | ≤ %/mo | Customers |
|---|---|---|
| Best-in-class (≤1%/mo) | 1% | Over |
| Healthy SMB SaaS (≤3%/mo) | 3% | Over |
| Elevated / warning zone (≤5%/mo) | 5% | Pass |
Benchmark bands are illustrative industry references, not guarantees of business viability. This calculator is for educational purposes only and does not constitute financial or business-strategy advice.
How it works
Customer churn and revenue churn measure the same event — customers leaving — but from different angles. Customer churn divides lost headcount by starting headcount: if 5 of your 100 customers leave, that is 5% customer churn regardless of their contract size. Revenue churn divides lost MRR by starting MRR: if those same 5 customers were all enterprise accounts, their departure might represent 40% of MRR while the headcount churn was only 5%. This divergence is the most common source of misread retention metrics. When customer churn looks mild but revenue churn looks severe, your best accounts are leaving; when revenue churn is low despite high customer churn, it is the small-contract customers cycling out.
Monthly-to-annual conversion uses compounding, not multiplication. The correct formula is 1 − (1 − r)^12, where r is the monthly rate expressed as a decimal. At 3%/mo, this gives 30.6%/yr — not 36% (= 3 × 12). The ×12 shortcut overstates annual churn because it ignores that each month's customer base is smaller than the previous month's. As monthly churn rises the gap widens: at 5%/mo the naïve annual would be 60%, while the compounded figure is about 46%. Using the correct formula matters most when projecting end-of-year cohort size or presenting annual metrics to investors.
Average customer lifetime is the reciprocal of the monthly churn rate: 1 ÷ (monthly rate as a decimal), expressed in months. At 5%/mo churn that is 20 months; at 1%/mo it is 100 months. This figure feeds directly into CAC : LTV models — LTV = ARPA × gross margin × avg lifetime, so halving churn more than doubles LTV. Net Revenue Retention (NRR) extends the picture by adding expansion MRR from upsells and upgrades: NRR = (starting MRR − lost MRR + expansion MRR) / starting MRR × 100. NRR above 100% means existing customers are growing your revenue even before counting new ones — the defining characteristic of best-in-class SaaS companies.
Frequently asked questions
Why is my revenue churn so different from my customer churn?+
Customer churn counts heads; revenue churn counts dollars. They diverge whenever your customer base is not uniformly sized. If you lose 2% of customers but those customers represent 15% of MRR, your revenue churn is 15% — not 2%. The reverse is also common: high customer churn concentrated among small-contract trial users can coincide with low revenue churn if your enterprise segment is sticky. Neither number tells the full story alone. Customer churn predicts operational load (support, onboarding replacements); revenue churn predicts whether the business is actually growing or shrinking in dollar terms. Use both.
Why should I use compounding instead of multiplying monthly churn by 12?+
Because you cannot churn customers you no longer have. If you start the year with 1,000 customers and lose 3% per month, month 1 loses 30 customers, but month 2 starts with only 970 — so it loses roughly 29, not 30. By year-end you have about 694 customers left, meaning you lost approximately 31% — not 36% (= 3 × 12). The compounding formula captures this shrinking base exactly. The error from ×12 grows with the monthly rate: at 1%/mo the gap is small (12% vs 11.4%), but at 5%/mo it is large (60% vs 46%). Always use 1 − (1 − r)^12 for annual figures in board decks and investor materials.
What does Net Revenue Retention above 100% actually mean?+
It means your existing customer cohort is growing in dollar terms without counting any new customers at all. If you start the period with $100,000 MRR, lose $5,000 to churn, but gain $10,000 from upsells and expansions, your NRR is 105%. Companies with NRR consistently above 120% — like many best-in-class cloud infrastructure or data platforms — can grow revenue purely from their existing base even if they sign zero new deals. NRR is a signal of product-market fit depth and pricing leverage. Values below 90% indicate that churn is actively shrinking the business faster than expansion can compensate. This calculator does not constitute financial or business-strategy advice.