I only know retention rate — how do I get customer lifespan?

Use the Retention rate option, or convert it to churn first: [math]Churn = 1 - Retention[/math] then [math]Lifespan_{periods} = frac{1}{Churn}[/math].

Why does 5% monthly churn show 20 months — is that “accurate”?

It’s the standard expected-value model assuming a constant churn probability each period: [math]Lifespan_{months}=frac{1}{Churn_{monthly}}[/math] (so [math]1/0.05 = 20[/math]). Real customers won’t churn exactly on month 20; it’s an average expectation.

Should I use logo churn or revenue churn for this calculator?

Use logo/account churn to estimate customer lifespan. Revenue churn is for revenue retention metrics (GRR/NRR) and can mislead lifespan because expansion/contraction affects revenue, not whether the customer exists.

My churn is quarterly or annual — can I still estimate an average lifespan in months/years?

Yes. Pick the matching Churn period (Quarterly/Annually). The calculator converts the expected lifespan into months/years from that period’s churn assumption (constant per period).

Customer Lifespan Calculator (From Churn or Retention)

Customer Lifetime (Average Customer Lifespan) Calculator

Estimate the average time a customer stays active using a churn (or retention) rate. Clean, practical UX with scenarios and a short “What It Means” interpretation.

Churn period

Your churn/retention rate is measured per month.

I have

Use churn when you track the % of customers who cancel in the period.

Monthly churn rate

Quarterly churn rate

Annual churn rate

Monthly retention rate

Quarterly retention rate

Annual retention rate

Results

Average customer lifespan (months)
Average customer lifespan (years)

What is Customer Lifetime (Average Customer Lifespan)?

Customer Lifetime (Average Customer Lifespan) is the expected length of time an average customer remains active before churning, measured in the same period as your churn/retention (monthly, quarterly, annually).

It matters because lifespan is a core driver of customer economics—especially LTV/CLV, LTV:CAC, CAC payback period, and the sustainability of MRR/ARR growth under different churn scenarios.

Formula

Example

Assume your churn period is monthly and you track churn rate.

Monthly churn rate: 5% ⇒
Average customer lifespan (months):
Average customer lifespan (years):

If you track retention rate instead:

Monthly retention rate: 95% ⇒
Lifespan stays:

How to Use the Customer Lifetime (Average Customer Lifespan) Calculator

Choose the period your churn/retention is measured in, enter either churn or retention, then read the estimated average customer lifespan in months and years.

Pick your churn period
- Select Monthly, Quarterly, or Annually based on how you track churn/retention.
Choose what you have
- - Select Churn rate if you track cancellations/losses.
- Select Retention rate if you track the % that stays active.
Enter your rate
- Input the percentage for the selected period.
Review the results
- Check Average customer lifespan (months) and (years).
Compare scenarios / share
- - Use Scenarios (if available) to test different churn/retention assumptions.
- Click Share / Embed to distribute the calculation, and Show charts if you want a visual.

Frequently Asked Questions

Use the Retention rate option, or convert it to churn first: then .
It’s the standard expected-value model assuming a constant churn probability each period: (so ). Real customers won’t churn exactly on month 20; it’s an average expectation.
Use logo/account churn to estimate customer lifespan. Revenue churn is for revenue retention metrics (GRR/NRR) and can mislead lifespan because expansion/contraction affects revenue, not whether the customer exists.
Yes. Pick the matching Churn period (Quarterly/Annually). The calculator converts the expected lifespan into months/years from that period’s churn assumption (constant per period).

Methodology & Sources

Bibliography

Sunil Gupta et al. (2006). Modeling Customer Lifetime Value — Journal of Service Research (SAGE Publications) https://www.anderson.ucla.edu/sites/default/files/documents/areas/fac/marketing/JSR2006%280%29.pdf
Accessed 2025-12-16
Peter S. Fader; Bruce G. S. Hardie (2007). How to Project Customer Retention — Journal of Interactive Marketing (Wiley) https://faculty.wharton.upenn.edu/wp-content/uploads/2012/04/Fader_hardie_jim_07.pdf
Accessed 2025-12-16
Phillip E. Pfeifer; Paul Farris (2014). Customer Lifetime Value (Darden Technical Note UVA-M-0800, Rev. Jun. 19, 2014) — University of Virginia Darden School of Business (Darden Case Collection via SSRN) https://papers.ssrn.com/sol3/Delivery.cfm/UVA-M-0800.pdf?abstractid=2974685&mirid=1
Accessed 2025-12-16

Customer Lifetime (Average Customer Lifespan) Calculator

Results

What It Means

What is Customer Lifetime (Average Customer Lifespan)?

Formula

Example

How to Use the Customer Lifetime (Average Customer Lifespan) Calculator

Pick your churn period

Choose what you have

Enter your rate

Review the results

Compare scenarios / share

Frequently Asked Questions

Methodology & Sources

Bibliography

Other Calculators in SaaS Metrics

Average Order Value (AOV) Calculator

Gross Revenue Retention Calculator

SaaS Rule of 40 Calculator

Average Revenue Per User (ARPU) Calculator

SaaS Magic Number Calculator

Annual Recurring Revenue (ARR) Calculator