Do I include new signups in “Still active from this cohort”?

No. Only count users/customers from the original cohort who are still active after the selected time period. Including new signups inflates retention and breaks cohort logic.

What exactly counts as “active” for cohort retention?

Use one meaningful action tied to value (e.g., logged in + completed a key action, created a project, sent an invoice). Don’t use vanity activity like “visited site” unless that’s genuinely your value moment.

Should I measure cohort retention in weeks, months, quarters, or years?

Match your product’s usage cycle. Weekly for daily/weekly habit products, monthly for subscription SaaS, quarterly for enterprise/long sales-cycle workflows, yearly for long-term memberships or renewals.

My retention looks “good” but revenue is flat—what am I missing?

Retention can be stable while expansion is weak. Pair cohort retention with Net Revenue Retention (NRR), Expansion MRR, and ARPA/ARPU to see whether retained users are growing spend or just sticking around at the same level.

Cohort Retention Calculator (Weekly/Monthly) – Retention Rate & Cohort Churn

Cohort Retention Calculator

Calculate cohort retention (and churn) over a selected timeframe using only the original cohort (exclude new users/customers). Includes tooltips, scenarios, and a short “What It Means?” interpretation.

Time unit

Use monthly cohorts (e.g., Month 0 → Month 3 retention).

Number of time units

Cohort size at start

Still active from this cohort

Results

Cohort retention %
Cohort churn %
Retained from cohort
Lost from cohort

What is Cohort Retention?

Cohort retention is the percentage of users/customers from the same start group (a “cohort”) who are still active after a specific number of time units.

It matters because retention is the backbone of value creation in recurring models: it drives LTV, improves CAC Payback Period, stabilizes cash flows, and sets the ceiling for metrics like NRR/GRR and efficient growth (Rule of 40, Burn Multiple).

Formula

Example

A cohort starts with 1,000 customers. After 3 weeks, 650 are still active.

How to Use the Cohort Retention Calculator

Set the time window and cohort size, enter how many from that original cohort are still active at the end of the window, and the calculator will return retention and churn plus retained/lost counts.

Pick your time unit
- Choose Weeks, Months, Quarters, or Years based on how often users should naturally return.
Set the number of time units
- Enter how long you’re measuring (e.g., 3 weeks = retention after 3 weeks).
Enter your cohort size and active users
- Fill “Cohort size at start” (users/customers at the start) and “Still active from this cohort” (how many from that same cohort remain active at the end).
Read the results panel
- Use “Cohort retention” and “Cohort churn” for % metrics, and “Retained/Lost from cohort” for absolute counts.
Share or visualize (optional)
- Use Share/Embed for reporting, and toggle charts (if available) to show the retention trend more clearly.

Frequently Asked Questions

No. Only count users/customers from the original cohort who are still active after the selected time period. Including new signups inflates retention and breaks cohort logic.
Use one meaningful action tied to value (e.g., logged in + completed a key action, created a project, sent an invoice). Don’t use vanity activity like “visited site” unless that’s genuinely your value moment.
Match your product’s usage cycle. Weekly for daily/weekly habit products, monthly for subscription SaaS, quarterly for enterprise/long sales-cycle workflows, yearly for long-term memberships or renewals.
Retention can be stable while expansion is weak. Pair cohort retention with Net Revenue Retention (NRR), Expansion MRR, and ARPA/ARPU to see whether retained users are growing spend or just sticking around at the same level.

Methodology & Sources

Bibliography

Not listed (2025). Retention Rate and Student Success — University of Arkansas for Medical Sciences (UAMS) – Academic Affairs https://academicaffairs.uams.edu/irpa/office-of-institutional-studies/student-outcomes/student-success/
Accessed 2025-12-16
Deborah Imbriglio (2025). Retention Analysis — University of Massachusetts Dartmouth – Office of Institutional Research and Assessment https://www.umassd.edu/oir/institutional-research/retention-analysis/
Accessed 2025-12-16
Mixpanel Team (2024). Ultimate guide to cohort analysis: How to reduce churn and strengthen your product retention — Mixpanel (Signals & Stories) https://mixpanel.com/blog/cohort-analysis/
Accessed 2025-12-16

Cohort Retention Calculator

Results

What It Means?

What is Cohort Retention?

Formula

Example

How to Use the Cohort Retention Calculator

Pick your time unit

Set the number of time units

Enter your cohort size and active users

Read the results panel

Share or visualize (optional)

Frequently Asked Questions

Methodology & Sources

Bibliography

Other Calculators in SaaS Metrics

Customer Churn Rate (Logo Churn) Calculator

Gross Revenue Retention Calculator

Net Revenue Retention (NRR) Calculator