SaaS Growth Ceiling Calculator
Find the ARR your current churn rate will let you reach, and how much of it you have already used up.
What this calculates
This works out the ARR level at which new sales exactly replace churned revenue, which is the ceiling your current retention imposes. It assumes your new MRR and your churn rate both hold steady. Neither does in practice, so treat the ceiling as the level you are heading toward rather than a date in the calendar.
At typical inputs for a B2B SaaS company adding $95,000 of new MRR a month against 2.8% monthly gross churn, this calculator puts the ARR ceiling at $40.7M, and a company at $6.4M of ARR has used 16% of it.
Your numbers
Acquisition
Retention
Where you are now
Results update as you type. Nothing is sent anywhere, the calculation runs in your browser.
ARR ceiling at this churn rate
Live$40.7M
You are at 16% of it today, on $6.4M of ARR
- Months to 80% of ceiling
- 51 months
- Ceiling at 2.0% churn
- $57.0M
- Annual churn equivalent
- 29%
Healthy
You have room. At this churn rate new sales still outrun the leak, so the ceiling is not the thing limiting you today. Sales capacity is. Revisit this the moment churn moves, because the ceiling falls faster than it rises.
Pressure-test this against your real numbers
Thirty minutes on which lever moves your ceiling first, and what it costs to pull.
No email required to see your result. The field above exists only if you want a copy.
How is this calculated?
A subscription business reaches equilibrium when the revenue it adds each month equals the revenue it loses. Dividing monthly new MRR by the monthly churn rate gives that equilibrium MRR, and twelve times that is the ARR ceiling. The months figure comes from the same recurrence, solved for the point where you reach four fifths of the way there.
Formula
ARR ceiling = (new MRR ÷ monthly churn) × 12 MRR(t) = ceiling + (MRRnow − ceiling) × (1 − churn)t Months to 80% = ln(0.2 × ceiling ÷ (ceiling − MRRnow)) ÷ ln(1 − churn) Annual churn equivalent = 1 − (1 − monthly churn)12
- New MRR is held flat. If you are still adding sales capacity, the real ceiling is higher and moves as you hire.
- Churn is gross revenue churn before expansion, the same monthly figure the Churn Rate Calculator produces. If you run net revenue retention above 100%, this ceiling understates you, and the Valuation Simulator is the better tool.
- The ceiling is an asymptote. You approach it and never reach it, which is why the months figure targets 80% rather than 100%.
- Seasonality, contract length and annual prepayment are all ignored. Everything is treated as a smooth monthly rate.
When this number misleads
If a meaningful share of your churn is one cohort with a fixable problem, a bad onboarding batch or a single segment you should never have sold to, then this ceiling describes a company you are not going to be in six months. The formula treats churn as a property of the business rather than of a group of customers. It cannot see the difference, and that difference is usually where the answer is.
Questions founders ask about this
Why is the ceiling so much higher than my ARR?
Because the ceiling is where you end up if nothing changes, not where you are. The gap between the two is your remaining runway on current retention. A large gap is good news, and it also means churn is not yet your binding constraint.
What if my churn is already under 2%?
Then the comparison metric uses half a point below your current rate instead, because a target you have already passed tells you nothing. Below about 1% monthly the ceiling gets so large that it stops being a useful planning number.
Should I use gross or net churn here?
Gross. Net churn nets expansion revenue against losses, and expansion is not capped by this formula in the same way. Feeding a net figure in will produce a ceiling that is too flattering, or an infinite one if your net churn is negative.
Do you store what I enter?
No. The calculation runs in your browser and nothing is transmitted. Your last inputs are saved in your own browser so the page remembers them when you return. If you use the email field, only the result summary and your address are sent.
Book a 30-minute product strategy session
Bring the ceiling you just calculated. We will work out which lever closes the gap fastest.
Book a strategy sessionNo pitch deck. No follow-up sequence.