Cohort Retention & LTV Calculator
Free tool · by Daniel HaketRetention is where SaaS lives or dies. Enter your cohort size, revenue per user and monthly retention, and this plots the retention curve and calculates average customer lifetime and lifetime value — the cohort analysis you'd normally build in a spreadsheet or pay an analyst for.
Why retention beats acquisition
Retention compounds: a customer who stays paying every month is pure profit after you've won them. Average customer lifetime is 1 ÷ (1 − monthly retention) — so 90% retention means an average life of 10 months, but 95% doubles it to 20. That's why a few points of retention move LTV more than almost anything on the acquisition side. The curve shows how fast your cohort melts away; the flatter it is, the more valuable every customer you win becomes.
Frequently asked questions
What is customer lifetime value (LTV)?
The total revenue you expect from a customer over their lifetime. It's roughly your revenue per user times their average lifetime, which retention drives.
How is average customer lifetime calculated?
As 1 ÷ (1 − monthly retention rate). At 90% retention, that's 10 months; at 95%, 20 months. Small retention gains extend lifetime — and LTV — a lot.
Why does retention matter more than acquisition?
Retained customers cost nothing extra and compound into profit, while acquisition costs money every time. Improving retention lifts LTV across every customer you already have.
How do I track real cohort retention?
This uses a single retention assumption; your real cohorts vary. A dashboard tool like Databox pulls actual retention and LTV from your billing data.
More free growth & marketing metrics
This tool is free and runs entirely in your browser. The link above is an affiliate link: we may earn a commission if you sign up, at no extra cost to you, and it never changes our honest take.