SaaS calculators
Subscription metrics are simple arithmetic that turns misleading the moment two people define one of them differently, and churn is the worst offender: by customer or by revenue, monthly or annualised, each telling a different story about the same business. These name their definitions rather than assuming yours.
Customer Acquisition Cost CalculatorFully-loaded acquisition spend divided by customers acquired, with payback period and the LTV ratio that decide whether it is affordable. The definition argument is what counts as fully loaded: salaries and tooling belong in it, and leaving them out flatters the number.Customer Lifetime Value CalculatorLifetime value in undiscounted and discounted form, with the CAC ratio. The undiscounted figure overstates at low churn, because money arriving four years out is not worth its face value today.LTV to CAC Ratio CalculatorThe ratio of what a customer is worth to what they cost to acquire. Three times is the conventional floor; much above five usually means underspending rather than efficiency.CAC Payback Period CalculatorHow long a customer takes to repay what they cost to win. Cash-flow reality that the LTV:CAC ratio hides. A 4× ratio over five years still starves a business of cash.Churn Rate CalculatorCustomer and revenue churn, with net churn after expansion. The two measures often disagree, and net revenue churn below zero is the state that lets a subscription business grow without acquiring anyone.Retention Rate CalculatorRetention measured properly. New customers subtracted out, so growth cannot disguise churn.Net Revenue Retention CalculatorNet revenue retention from a fixed cohort, with gross retention alongside. Above 100% the existing base grows on its own; gross retention shows what that number is hiding.MRR and ARR CalculatorMRR and ARR from a mix of monthly and annual contracts. Annual deals are normalised to a monthly rate rather than counted when they are billed.ARPU CalculatorRevenue per active user. The definition of "active" does more work here than the arithmetic does.Cohort Revenue CalculatorRevenue from one cohort as it decays. Retention compounds, so 92 percent monthly leaves under a third of the cohort after a year, which is why small retention differences dominate everything else.Rule of 40 CalculatorGrowth plus margin. The heuristic is that a software business should clear 40 on the sum of the two, trading one against the other freely.SaaS Magic Number CalculatorNew ARR divided by the previous quarter's sales and marketing spend. Above 0.75 the standard advice is to spend more; below 0.5, to fix efficiency first.