# SaaS metrics definitions How to define and report MRR, ARR, churn, net revenue retention, CAC and customer lifetime value consistently. Formulas only, no benchmarks. Canonical URL: https://worldenterprise.org/research/early-stage-saas-metrics-definitions/ Last updated: 2026-10-06 Publisher: World Enterprise, run by World Enterprise Group Incorporated ## Summary Early-stage companies are asked for the same handful of numbers by every investor, advisor and customer, and report them differently each time. The cost is not the arithmetic; it is that two reports of "churn" cannot be compared unless the definition is the same. This brief collects the published definition and formula for each metric, says where a formula is not stated by the references, and proposes a short discipline for reporting them consistently. Every figure in this brief is a formula or a symbol. There are no benchmarks, no typical values and no targets. ## Definitions and formulas ### Recurring revenue: MRR and ARR "Recurring revenue is often tracked on either a monthly basis, as monthly recurring revenue (MRR), or an annual basis, as annual recurring revenue (ARR)" [(ARR entry)](#source-wiki-arr). The entry describes MRR as the average monthly client payment multiplied by the number of clients, and one-time fees are excluded. The entry does not give a formula converting MRR to ARR. A common convention is to multiply a monthly figure by twelve. That convention is not stated by the references used here, so it is treated as a reporting choice: say which one you use. ### Customer churn Churn rate "is a metric that measures the proportion of individuals (e.g. employees), customers, or items that leave a defined group during a specified period of time." For customers the entry gives Churn = (L / T) x 100, where L is customers lost and T is total customers during the time period [(Churn entry)](#source-wiki-churn). The entry notes an alternative that divides by customers acquired in the period instead of total customers, which is a different metric and must be labelled as such. ### Net revenue retention "Net revenue retention (NRR) is a metric that measures a company's ability to retain revenue from existing customers over a specific period of time." The formula as shown is: NRR = [(beginning recurring revenue - MRR lost from churn - MRR lost from downgrades + revenue from upgrades) / beginning recurring revenue] x 100 [(Stripe)](#source-stripe-nrr) ### Customer acquisition cost "Customer acquisition cost (CAC) is the cost of persuading a customer to purchase a product or service." The simple form is CAC = MCC / CA, marketing cost for the period divided by customers acquired in it. An extended form adds sales and marketing wages, software, professional services and overhead [(CAC entry)](#source-wiki-cac). The choice between simple and extended changes the number, so state which you use. ### Customer lifetime value LTV, or customer lifetime value (CLV), is "the net profit that a customer contributes to during the entire future relationship with a business." The basic formula shown is CLV = Margin x (Retention / (1 + Discount - Retention)), where the discount term reflects the time value of money [(CLV entry)](#source-wiki-clv). The CAC entry notes that a ratio of lifetime value to acquisition cost is sometimes quoted as a target; this brief records that the idea exists and publishes no target, because a rule of thumb is not a benchmark. ## Analysis: reporting consistently This section is analysis by World Enterprise Editorial. It is a recommendation, not a statement of the references. 1. **Fix the period.** Report each metric over a stated period, and the same period each time. 2. **Fix the population.** Say which customers are in the denominator: all, paying only, or one cohort. 3. **Separate recurring from one-time.** The MRR entry excludes one-time fees; keep them out of every recurring metric. 4. **State the conversion convention.** If ARR is derived from MRR, write down the rule. 5. **Pair the number with its formula.** A reader should be able to recompute it from your inputs. 6. **Never mix simple and extended CAC in one trend line.** If the definition changes, restate the history. 7. **Do not quote a ratio without its inputs.** A ratio of two derived metrics hides both definitions. ## Methodology On 6 October 2026 the five references listed under Sources were retrieved. For each metric the quotation and formula are reproduced as returned by the retrieval tool. A formula the references do not state is marked as a convention. Symbol meanings (MCC, CA, L, T) are as read from the page summaries. Nothing in this brief is a measured value. ## Limitations - The references are one payments-company explainer and four encyclopedia entries. None is an accounting standard, and none replaces the definitions in a company's financial reporting framework. - The MRR to ARR conversion is not stated by the references and is a convention here. - Symbol expansions were read from page summaries and should be confirmed against the pages. - Other widely used references (for example Investopedia and Stripe's MRR page) could not be retrieved, so they are not cited. - The brief gives no benchmarks. Do not infer one from an example. ## Appendix: formula table and reporting checklist | Metric | Formula as published | Reference | Note | |---|---|---|---| | MRR | Average monthly client payment x number of clients; one-time fees excluded | [ARR entry](#source-wiki-arr) | Define "client" and "payment" | | ARR | Recurring revenue on an annual basis | [ARR entry](#source-wiki-arr) | Conversion from MRR is a stated convention | | Customer churn | (Customers lost / Total customers during period) x 100 | [Churn entry](#source-wiki-churn) | State the period and the population | | NRR | [(Beginning recurring revenue - MRR lost from churn - MRR lost from downgrades + revenue from upgrades) / Beginning recurring revenue] x 100 | [Stripe](#source-stripe-nrr) | Existing customers only | | CAC, simple | MCC / CA | [CAC entry](#source-wiki-cac) | Marketing cost over customers acquired | | CAC, extended | Simple form plus sales and marketing wages, software, professional services, overhead | [CAC entry](#source-wiki-cac) | Label which form is used | | CLV | Margin x (Retention / (1 + Discount - Retention)) | [CLV entry](#source-wiki-clv) | Basic form only | Reporting checklist, each item answered in writing for every metric you report: 1. What is the period? 2. Who is in the population? 3. Are one-time fees excluded? 4. Which formula variant is used? 5. Has the definition changed since the last report? 6. Can a reader recompute the number from the inputs given? ## Methodology Collects the definition and formula each of five public references gives for a metric, reports them as written, flags any formula the references do not state, and adds a labelled reporting-consistency checklist. ## Limitations The references are an explanatory payments page and encyclopedia entries, not accounting standards. The ARR-as-twelve-times-MRR convention is not stated by the references used. Symbol expansions come from page summaries. The brief gives no benchmarks and no target values. ## Sources - Net revenue retention (NRR). Stripe. - Annual recurring revenue. Wikipedia. - Customer acquisition cost. Wikipedia. - Customer lifetime value. Wikipedia. - Churn rate. Wikipedia.