Unit Economics Calculator (CAC / LTV)
Do you make more from a customer than it costs to acquire one? Enter your acquisition spend and retention numbers to get CAC, LTV, the LTV:CAC ratio, and payback months — with plain-English verdicts. Everything runs in your browser.
About this tool
This uses the textbook SaaS definitions: CAC is fully-loaded sales and marketing spend divided by customers acquired, and LTV is gross-margin-adjusted revenue divided by monthly churn — which is just the geometric-series result of a customer surviving churn month after month. The 3:1 ratio and 12-month payback benchmarks are the ones investors most commonly quote; they are rules of thumb, not laws, and capital-efficient bootstrapped businesses can thrive well outside them.
Be honest with the inputs and the outputs will be honest with you: blended churn hides cohort differences, ARPU drifts as your mix shifts, and CAC measured in a month of heavy spend overstates the steady state. Nothing you type leaves the page — no server, no upload, no tracking of tool inputs.