Canonical formula calculator
RETENTION RATE
What percentage of your customers stick around — and what percentage you have to replace just to stay flat.
How many customers from the start of the period are still active at the end. Does NOT include new customers acquired during the period.
How many active customers you had at the beginning of the period.
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Add context for case suggestions
Optional — helps us match this calculation against relevant case studies (coming soon).
What this tells you
Retention rate is the percentage of customers from the start of a period who are still your customers at the end. It is the most direct measure of whether what you sell keeps people coming back. Monthly retention above 95% is excellent for most B2B SaaS; under 90% means you are running fast just to stand still.
When to use it
Calculate retention every month and watch the cohort trend over time. Retention that is improving means you are getting better at keeping customers. Retention that is flat or declining while you are growing means you are masking churn with new acquisition — and that math eventually catches up.
What it doesn’t tell you
Retention rate by itself does not tell you which customers are leaving. Losing 5% of small customers is a different reality than losing 5% of your largest. Pair retention with revenue retention (which weights by customer value) for the full picture.
Coming soon
Cases, plays, and benchmarks for this metric will appear here as the Moonshot knowledge libraries grow. For now: log in to track your number over time and Moonshot will surface trend warnings when the substrate fills in.