Use one period and one set of definitions
This fictional subscription company starts a month with 100 paying customers and $10,000 of monthly recurring revenue. Its founder wants to know whether growth supports a larger acquisition budget. The example uses simplified management metrics, not accounting revenue recognition or investment advice.
Choose a month-end cutoff, normalize annual subscriptions to a monthly amount, and keep setup fees out of recurring revenue. Use the same definition for discounts, delinquent accounts, and cancellations every month. A customer count drawn from today and revenue drawn from last month will produce a misleading average even when both source reports are correct.
Reconcile the movement in MRR
| Movement | MRR |
|---|---|
| Opening MRR | $10,000 |
| New subscriptions: 10 customers | +$1,200 |
| Expansion from existing customers | +$600 |
| Contraction from existing customers | −$200 |
| Cancellations: 5 customers | −$500 |
| Closing MRR | $11,100 |
The bridge is $10,000 + $1,200 + $600 − $200 − $500 = $11,100. Compare it with the MRR Calculator and ARR Calculator. Multiplying closing MRR by twelve gives a $133,200 annual run rate. That is not cash already collected, a booked contract total, or a prediction that the next twelve months will produce exactly that revenue.
Separate customer retention from revenue retention
Five cancellations from 100 opening customers produce 5% monthly customer churn. Do not divide by the 105 closing customers: new acquisitions would hide some of the loss. Gross revenue retention is ($10,000 − $200 − $500) ÷ $10,000 = 93%. Net revenue retention includes expansion: ($10,000 + $600 − $200 − $500) ÷ $10,000 = 99%.
Enter these opening-cohort movements in the Churn Calculator. New subscriptions do not belong in net revenue retention. This business grew overall, but its existing customer base shrank in recurring revenue. A founder who looks only at 11% MRR growth can miss that distinction.
Ask how long acquisition takes to repay
Assume $6,000 of fully loaded acquisition cost produced those ten new paying customers, with no material conversion lag for this simplified example. CAC is $600 per customer. Include allocated sales and marketing labor as well as advertising; $2,000 of ad spend alone would incorrectly suggest $200 CAC. Use the Customer Acquisition Cost Calculator to make the cost definition explicit.
For a separate, stable illustrative cohort, assume $100 monthly revenue per customer, an 80% gross margin, and 5% monthly customer churn. Monthly gross profit per customer is $80. The simple churn-based LTV estimate is $80 ÷ 0.05 = $1,600. The LTV:CAC ratio is about 2.67 and gross-margin payback is $600 ÷ $80 = 7.5 months. Reproduce these assumptions in the LTV Calculator and LTV to CAC Ratio Calculator.
At 8% monthly churn, the same simplified LTV falls to $1,000 and the ratio to about 1.67. Payback remains 7.5 months under the formula, but fewer customers may survive long enough to repay acquisition. A ratio alone does not tell you whether the next marketing campaign is affordable.
Check where the averages stop being useful
The reciprocal-churn LTV model assumes a stable churn rate and stable contribution over time. A small, young cohort with one unusual cancellation month is weak evidence for lifetime behavior. Zero observed churn does not establish infinite value. Compare customer groups by acquisition month, plan, and channel, and use observed gross profit and retention as history develops.
Keep margins consistent. If payment processing and hosting are already included in cost of service, do not subtract them again. Use the Stripe Fee Calculator for the relevant payment assumptions and the SaaS Pricing Calculator to explore a pricing scenario. Check the official provider pricing linked on the fee page before using a rate in a budget.
Decide what to investigate next
- Reconcile the MRR bridge with subscription records and explain adjustments.
- Review cancellations and contractions in the opening cohort before celebrating new sales.
- Match acquisition costs to the customers they helped acquire, allowing for the sales cycle.
- Compare payback with available cash and the timing of customer collections.
- Record one hypothesis to test, such as whether a channel attracts customers who retain longer, and revisit it with the next cohort.
In this example, the useful next step is to understand retention and acquisition quality before raising the budget. The calculators make the arithmetic repeatable; customer conversations, reconciled records, and cohort history supply the evidence behind the decision.