Churn Rate

Churn rate is the percentage of customers or revenue lost in a given period. It is the single most important health metric for any subscription business because compounding churn destroys MRR faster than almost any acquisition problem. A high churn rate means your growth engine is leaking from the bottom.

formula.sh

Churn Rate = (Customers Lost in Period / Customers at Start of Period) × 100

> Customers Lost in Period — cancellations and non-renewals that occurred during the window
> Customers at Start of Period — your active customer count at the beginning (not end)
> Multiply by 100 to express as a percentage
> Typically measured monthly (MCR) or annually (ACR)

example

example.sh

You start January with 400 customers and lose 20 by month end.

(20 / 400) × 100

→ 5% monthly churn rate — which compounds to ~46% annual churn. You are replacing nearly half your base every year.

why it matters

Churn rate directly caps your growth potential. At 5% monthly churn, every new customer you acquire only stays for an average of 20 months. Your sales team is running on a treadmill that accelerates as you scale.

Investors treat churn as a proxy for product-market fit. World-class B2B SaaS sits at 0.5–2% monthly churn. Consumer SaaS often runs 3–8%. If you are above those ranges, no amount of acquisition spend fixes the problem — you are filling a leaky bucket.

The compounding math is brutal. A 5% monthly churn rate means roughly 46% annual churn. A 2% monthly rate means ~22% annual churn. That difference determines whether you build a durable business or a perpetual-motion fundraising machine.

common mistakes

✗Measuring churn by dividing by end-of-period customers instead of start-of-period, which understates the rate.

✗Ignoring revenue churn entirely and only tracking logo churn — a few large churned accounts can be catastrophic even if customer count looks stable.

✗Confusing gross churn with net churn; expansion revenue can mask serious underlying retention problems.

pro tips

✓Segment churn by cohort, plan tier, and acquisition channel — aggregate churn hides the segments dragging you down.

✓Calculate churn using a trailing 3-month average to smooth out seasonal noise and one-off spikes.

✓Map churn events back to product usage patterns 30–60 days prior to identify leading indicators, not lagging ones.

the mrrsucks take

Your churn rate isn't a metric, it's a countdown timer on your startup's life. At 5% monthly you're not building a SaaS — you're running a very expensive revolving door.

faq

What is a good churn rate for SaaS?+

Best-in-class B2B SaaS targets under 1% monthly (under 12% annually). SMB-focused products typically see 3–5% monthly. Above 5% monthly is a red flag requiring immediate retention intervention.

Should I measure churn monthly or annually?+

Measure both. Monthly churn gives you faster feedback loops for experiments. Annual churn is what you present to investors and what cohort analysis requires for LTV calculations.

How do I reduce churn quickly?+

Start with exit interviews on every cancellation. Build a cancellation flow that captures reasons. Identify the top 2–3 cancellation reasons and fix the product or onboarding experience that causes them.

The churn spiral›

related metrics

./install-the-daemon

$9. 365 roasts. one public endpoint of pure shame.