SaaS MRR & ARR Calculator

MRR (monthly recurring revenue) is the predictable revenue your subscriptions generate in a month: subscribers multiplied by the average monthly price. ARR (annual recurring revenue) is simply MRR multiplied by 12 — the same figure on a yearly basis. This calculator shows both from the inputs you enter.

Each month, churn removes a share of your existing MRR. The calculator multiplies your MRR by the monthly churn rate to show how much you lose, then subtracts that from the new MRR you add to give net new MRR. The 12-month projection compounds this drag every month, so even a few points of churn can flatten growth over a year.

Average customer lifetime is estimated as 1 divided by the monthly churn rate, so 4% monthly churn implies a ~25-month average lifetime. Lifetime value (LTV) is then ARPU (average revenue per user) multiplied by that lifetime. With zero churn the lifetime is unbounded, so the tool leaves lifetime and LTV blank rather than showing infinity.

No — they are planning estimates. The model assumes a constant churn rate and a flat amount of new MRR added each month, and it ignores upgrades, downgrades, discounts, and reactivations. Use it to sanity-check a trajectory, not as a forecast or financial advice. Everything is calculated in your browser; nothing you enter is sent anywhere.