Churn rate calculator
Enter how many customers you started the period with and how many you lost. The calculator returns churn rate, the matching retention rate, and the annualized equivalent so you can compare a monthly figure against annual benchmarks.
Your numbers
Active accounts on day one of the window.
Accounts that cancelled or failed to renew.
Used to annualize. Enter 1 for monthly, 3 for quarterly, 12 for annual.
Churn rate (3-month period)
3.00%
12 of 400 customers lost
- Retention rate
- 97.00%
- Annualized churn
- 11.5%
- Monthly equivalent
- 1.01%
- Customers remaining
- 388
Formula
How the calculation works
Churn rate = (Customers lost ÷ Customers at start) × 100Annualized churn compounds the survival rate: 1 − (1 − churn)^(periods per year). Multiplying a monthly churn rate by 12 overstates annual churn, and the error grows as churn rises.
Getting it right
What most people get wrong
Use the same denominator every time
The most common error is including customers acquired during the period in the starting count. New customers have not had time to churn, so counting them deflates the rate and makes a worsening trend look stable. Count only the accounts that existed on day one.
Match the period to your contract length
Monthly contracts warrant monthly measurement. With annual contracts, monthly churn is noisy and misleading — most months will show zero because nothing was up for renewal. Measure annually and use renewal rate for in-period visibility.
Customer churn is not revenue churn
This calculator counts accounts, weighting a $2,000 customer the same as a $200,000 one. If your customer sizes vary meaningfully, revenue churn is the number that should drive planning. Losing one enterprise account can matter more than losing twenty small ones.
Separate involuntary churn before you act
Failed payments and expired cards can be a meaningful share of the total. That is a billing problem with a billing fix, and it is usually the cheapest churn to recover. Blending it into voluntary churn sends you looking for relationship causes that are not there.
FAQ
Questions, answered
How do you calculate churn rate?+
Divide the number of customers lost during a period by the number of customers at the start of that period, then multiply by 100. Do not include customers acquired during the period in the denominator — they have not had the opportunity to churn, and including them understates the rate.
What is a good churn rate?+
For enterprise B2B SaaS, 5–7% annually is healthy. SMB-focused products commonly see 15–25% annually because contracts are shorter and switching costs lower. Monthly churn above roughly 2% usually points to a product-market fit or onboarding problem rather than a retention execution problem.
How do you annualize a monthly churn rate?+
Compound the survival rate rather than multiplying: annual churn = 1 − (1 − monthly churn)^12. Multiplying monthly churn by 12 overstates the annual figure, and the error grows with the rate — 5% monthly is 46% annually, not 60%.
What is the difference between churn rate and retention rate?+
They are complements for the same population: retention rate = 100% − churn rate. Churn measures who left, retention measures who stayed. Revenue retention is often preferred in reporting because it can exceed 100% when expansion outpaces losses, which churn rate cannot express.
Keep going
Related tools and definitions
Other calculators
NRR calculator
Calculate net revenue retention and gross revenue retention from starting MRR, expansion, contraction, and churn — with benchmark context for B2B SaaS.
CLV calculator
Calculate customer lifetime value from ARPA, gross margin, and churn — plus your LTV:CAC ratio and payback period, with benchmark context.
Your next account move is already in the signals
The number is the easy part.
Aartha shows you which accounts are moving it, and the cited evidence behind why.