Every SaaS company eventually stops compounding — not because the market is gone, but because new sales catch up with churn. Plug in four numbers and see when growth stalls and where your MRR tops out. Pure math, no AI.
Starting customers, new sales per month, monthly churn %, and ARPU. Use real numbers if you have them — defaults are fine to explore.
Each month adds new sales and subtracts churned customers. MRR = customers × ARPU. We walk forward until growth flattens.
Stall is when growth starts feeling stuck (~75% of equilibrium). Ceiling is the MRR where new sales ≈ churn — your hard cap at this pace.
Paying customers you have today
Average net-new logos closed each month
% of customers who cancel each month
Average revenue per user, per month
At a fixed sales pace and churn rate, your customer base converges on an equilibrium: roughly new sales ÷ churn rate. Multiply by ARPU and you get the maximum Monthly Recurring Revenue this machine can sustain — the ceiling. Past that point, churn cancels out every new win.
Growth rarely feels “stuck” only at the absolute max. We mark a stall point near 75% of equilibrium — when the curve visibly flattens and each new month adds much less MRR. The ceiling is the hard cap if nothing else changes.
Knowing both dates helps you decide whether to push acquisition, cut churn, raise ARPU, or expand the product before you run into the wall.
Customers next month ≈ current customers + new sales − (current customers × monthly churn). Then MRR = customers × ARPU. We repeat that until growth slows to a crawl near equilibrium.
Example: 25 new sales / month and 10% churn → ~250 customers at equilibrium. At $37 ARPU that is about $9,250 MRR — your ceiling at that pace, no matter how long you wait.