Saas Metrics
SaaS subscription-finance and recurring-revenue metrics pack for founders, RevOps, growth analysts and investors modelling a subscription business: compute Monthly Recurring Revenue (mrr) and Annual...
saas-metrics
SaaS subscription-finance intelligence pack. Deterministic recurring-revenue, unit-economics and board-metric math for founders, RevOps and investors, with an optional AI commentary layer on the cohort and Rule-of-40 tools that activates only when a model is reachable (and silently falls back to the heuristic core otherwise).
Estimates for planning/benchmarking only — not financial or investment advice.
Tools
| Tool | Args | Does | ||
|---|---|---|---|---|
mrr | `{mrr \ | customers,arpu \ | plans[]}` | Monthly Recurring Revenue (+ ARR). Build from a flat number, customers×ARPU, or a plans:[{price,customers,period}] array. |
arr | `{arr \ | mrr \ | plans[]}` | Annual Recurring Revenue (+ implied MRR). |
arpu | {revenue, customers, expansion?, contraction?} | Average revenue per user/account, net of expansion/contraction. | ||
ltv | {arpu, churn, grossMargin?} | Lifetime value = ARPU × margin ÷ churn (constant-churn geometric model) + avg lifetime. | ||
churnRate | {startCustomers, lostCustomers, newCustomers?} | Churn %, retention %, end count, net change. | ||
retentionCohort | {cohorts:[{sizes:[…]}], options?} | Per-cohort retention %, averaged curve, stabilization flag. options.advise adds an AI read. | ||
quickRatio | {newMrr, expansionMrr, churnedMrr, contractionMrr} | SaaS Quick Ratio (growth efficiency) + grade. | ||
magicNumber | `{newArr \ | currentArr,priorArr; salesMarketingSpend}` | Sales Magic Number (efficiency) + implied payback. | |
ruleOf40 | {growthRate, profitMargin, options?} | Rule of 40 score, pass/fail, growth-vs-profit profile. options.advise adds an AI verdict. | ||
netRevenueRetention | {startingMrr, expansionMrr, contractionMrr, churnedMrr} | NRR + GRR %, ending MRR, grade. | ||
cac | `{spend, newCustomers \ | channels[]}` | Blended CAC, or per-channel CAC sorted cheapest-first. | |
paybackMonths | {cac, arpu, grossMargin?} | CAC payback period in months + grade. |
The two tools with an AI path (retentionCohort, ruleOf40) tag their result { mode: 'heuristic' | 'llm' }.
Example
import pack from './index.js';
await pack.adapters.ltv({ arpu: 100, churn: 0.05, grossMargin: 0.8 });
// { ltv: 1600, arpu:100, churnRate:0.05, grossMargin:0.8, avgLifetimeMonths:20, … }
await pack.adapters.netRevenueRetention({ startingMrr: 100000, expansionMrr: 15000, contractionMrr: 4000, churnedMrr: 6000 });
// { nrrPct:105, grrPct:90, endingMrr:105000, grade:'net-expanding', … }
await pack.adapters.quickRatio({ newMrr: 40000, expansionMrr: 10000, churnedMrr: 8000, contractionMrr: 2000 });
// { quickRatio:5, addedMrr:50000, lostMrr:10000, grade:'excellent', … }DRY boundaries
financeowns time-value-of-money (NPV, IRR, loan amortization, discounted cash flow);
numbers owns generic scalar math and series stats; tax owns income-tax withholding; invoice owns billing documents. This pack owns subscription-business composition — recurring-revenue aggregation, cohort retention, unit economics (LTV/CAC/payback) and the SaaS board ratios (Quick Ratio, Magic Number, Rule of 40, NRR/GRR) — which none of those own.
- Self-contained: the only cross-pack import is
../_shared/llm.jsfor the optional AI layer.
Hybrid intelligence
Every deterministic core runs offline with no model. retentionCohort and ruleOf40 accept options.advise:true to request LLM commentary; with no model configured/reachable they return the exact same numbers tagged mode:'heuristic'. A down model never throws.