Reviewed and updated: 24 October 2026.
A SaaS cohort table follows the same starting customers through time. It lets you compare retention, expansion and acquisition economics without mixing new customers into the result. This practical guide shows the inputs, calculations and checks needed to build three useful tables.
All figures below are hypothetical teaching examples. For interpreting a retention problem rather than building the spreadsheet, see SaaS cohort analysis for customer retention. For the wider metric definitions, use our SaaS KPI reference.
Set the cohort rule before opening the spreadsheet
Choose one start event, such as first paid subscription, and group customers by the month of that event. Keep a stable customer identifier and a calendar of reporting dates. Do not move an existing customer into a new cohort when they upgrade.
Record your policies for free trials, multiple subscriptions, cancellations, reactivations, pauses, credits, currency and customer mergers. The exact policy must suit your business, but it must remain consistent across the table.
At minimum, prepare customer ID, cohort month, observation month, active-customer flag, recurring monthly revenue and the relevant acquisition-cost allocation. Keep recognised revenue and cash collections in separate fields when analysing those measures.
Table 1: customer retention at the same age
| Cohort | Month 0 customers | Month 1 | Month 2 | Month 3 |
|---|---|---|---|---|
| January | 100 | 95 | 92 | 90 |
| February | 80 | 76 | 72 | Not yet observed |
| March | 60 | 57 | Not yet observed | Not yet observed |
Retention at age n = active customers from the original cohort at age n ÷ starting cohort customers. January’s Month 2 retention is 92 ÷ 100 = 92%. February’s Month 2 retention is 72 ÷ 80 = 90%.
Compare those Month 2 figures with each other. Comparing January Month 3 with March Month 1 confuses customer age with performance. Future periods must stay blank or be labelled not yet observed; entering zero would falsely imply that every customer churned.
In a spreadsheet, calculate the age in complete reporting months, count the relevant starting customers once, and divide each observed active count by that cohort’s starting count. Guard against a zero starting population and display unavailable periods explicitly.
Table 2: recurring revenue from the same cohort
| January cohort measure | Month 0 | Month 1 | Month 2 | Month 3 |
|---|---|---|---|---|
| Recurring monthly revenue | £10,000 | £9,800 | £10,000 | £10,500 |
| Net MRR retention against Month 0 | 100% | 98% | 100% | 105% |
| Customer retention | 100% | 95% | 92% | 90% |
Net MRR retention at Month 3 is £10,500 ÷ £10,000 = 105%. It can rise above 100% because retained customers may expand. The accompanying 90% customer retention shows that revenue expansion is offsetting customer losses.
Exclude new customers from this original cohort. Keep expansion, contraction, churn and reactivation movements identifiable. A constant-currency view may help distinguish commercial changes from exchange-rate effects, provided its method is stated.
For comparison, gross revenue retention excludes expansion. Do not label a table GRR if its numerator includes upselling. ChartMogul’s net MRR cohort documentation provides a useful reference for the subscription-based interpretation.
Table 3: gross-profit payback by acquisition cohort
Assume £30,000 of acquisition cost is allocated to a cohort. Its subsequent monthly gross profit is £7,000, £7,500, £8,000 and £8,500.
| Age | Monthly gross profit | Cumulative gross profit | Acquisition cost recovered? |
|---|---|---|---|
| Month 1 | £7,000 | £7,000 | No |
| Month 2 | £7,500 | £14,500 | No |
| Month 3 | £8,000 | £22,500 | No |
| Month 4 | £8,500 | £31,000 | Yes |
On this monthly observation basis, gross-profit payback occurs in Month 4. This is not the same as cash payback: invoice dates, collection timing and upfront costs can produce a different cash profile.
State which sales and marketing costs are included and how shared expenditure is allocated. Review the lag between spending and customer acquisition. A convenient calendar-month allocation can distort economics when sales cycles are long.
Reconcile before drawing conclusions
- Reconcile cohort starting customers to the customer system after documented exclusions.
- Reconcile total cohort MRR to the recurring-revenue report at every observation date.
- Explain differences between MRR, invoiced amounts and recognised revenue.
- Identify duplicates and customers whose IDs or billing systems changed.
- Keep unavailable future cells separate from observed zero revenue.
- Show cohort sizes so a very small group is not mistaken for a robust trend.
- Document cost allocation and distinguish gross-profit payback from cash payback.
The purpose is a table that can be reproduced, not merely a colour gradient. A rise in retention should lead to questions about customer mix, onboarding, product and contracts before being attributed to one intervention.
Turn the tables into a financial decision
Use the retention curve to challenge forecast renewal assumptions. Use cohort MRR to test whether expansion is repeatable across customer groups. Use payback to assess the timing of acquisition spending against available cash.
Do not mechanically project an immature cohort’s best early result across several years. Show a base case and a downside case, document the assumed maturity curve and revisit the forecast as evidence develops. Our SaaS financial model components guide explains how cohort assumptions connect with a complete forecast.
Frequently asked questions
What is a SaaS cohort table?
It follows a fixed starting group of customers across successive observation periods. Depending on the table, it may show active customers, recurring revenue, gross profit or cash collections.
Should customers be grouped by signup or first payment?
Choose the event that answers the question and state it clearly. A product activation analysis may use signup, while a paid-retention analysis may use first paid subscription. Do not silently combine different start events.
Why must future cohort cells remain blank?
A future period has not been observed. Showing zero would incorrectly record complete churn or zero revenue. Label unavailable periods and compare cohorts at the same age.
Can revenue retention increase while customer retention falls?
Yes. Remaining customers may expand enough to offset revenue lost from churned customers. Review customer retention, gross retention and net retention together.
Is CAC payback the same as cash payback?
No. Gross-profit CAC payback measures recovery through gross profit. Cash payback also depends on when costs are paid and customer invoices are collected.
Sources and further reading
Discuss your requirements
Need a cohort pack that reconciles to your billing and finance records? Discuss SaaS reporting and financial-model support, with the definitions, input owners and outputs agreed in advance.
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Over 12 years across Big Four audit, Investment Banking, and corporate advisory. Kish works with SaaS founders, tech companies, and ambitious UK SMEs from £1M to £50M in revenue on fundraising, valuations, exit planning, and financial strategy. ICAEW regulated. Big Four trained. Based in London.