Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
ARR lost to churn per year
$778,245
Effective annual churn rate
15.6%
Customers needed to replace it
56
Acquisition spend just to stand still
$611,479
Annual value of cutting monthly churn by 1 point
$543,456
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Got your number — what next?
Pick one, it takes 20 secondsHow to use this
- 1Enter current arr ($).
- 2Enter monthly logo churn rate (%).
- 3Enter average annual contract value ($).
- 4Enter customer acquisition cost ($).
- 5Read your arr lost to churn per year on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Churn has two costs: the recurring revenue you lose, and the acquisition spend needed to replace it before any growth counts. This calculator converts a monthly or annual churn rate into lost ARR, the number of new customers required to replace it, and the CAC bill for that replacement — the treadmill cost of standing still. It also shows what a one-point improvement in churn is worth annually, which is almost always a larger number than teams expect and usually justifies retention investment that gets deprioritised in favour of new-logo work.
Worked example
Using the values the calculator loads with:
Inputs
- Current ARR: 5000000 $
- Monthly logo churn rate: 1.4 %
- Average annual contract value: 14000 $
- Customer acquisition cost: 11000 $
Results
- ARR lost to churn per year: $778,245.42
- Effective annual churn rate: 15.6%
- Customers needed to replace it: 56
- Acquisition spend just to stand still: $611,478.54
- Annual value of cutting monthly churn by 1 point: $543,455.65
What each field means
Inputs
- Current ARR ($)
- The current arr used in the calculation, measured in $. Starts at 5000000 $ so you have a working example on load.
- Monthly logo churn rate (%)
- The monthly logo churn rate used in the calculation, measured in %. Starts at 1.4 % so you have a working example on load. Accepted range: 0–50 %.
- Average annual contract value ($)
- The average annual contract value used in the calculation, measured in $. Starts at 14000 $ so you have a working example on load.
- Customer acquisition cost ($)
- The customer acquisition cost used in the calculation, measured in $. Starts at 11000 $ so you have a working example on load.
Results
- ARR lost to churn per year
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Effective annual churn rate
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Customers needed to replace it
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Acquisition spend just to stand still
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual value of cutting monthly churn by 1 point
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why isn't annual churn just monthly churn times twelve?
Because churn compounds against a shrinking base. 2% monthly is about 21.5% annually, not 24% — the difference grows with the rate, and multiplying by twelve overstates losses at high churn rates.
Is logo churn or revenue churn the right measure?
Both, for different questions. Logo churn tells you about product-market fit and onboarding; revenue churn tells you about the P&L. If logo churn is high but revenue churn is low, you're losing small accounts that were never going to be profitable.
What's an acceptable churn rate?
For SMB self-serve, 3-5% monthly is common and 2% is good. For mid-market, under 1% monthly. For enterprise, annual gross churn under 10% and often under 5%. Compare within your segment — cross-segment benchmarks are misleading.
Where does churn reduction pay off most?
In the first 90 days. Most cancellations are decided during onboarding, when the customer either reaches a first value moment or doesn't. Retention spend aimed at month 11 renewals almost always underperforms spend aimed at week two activation.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Net Revenue Retention Calculator
Track expansion against churn to see if your existing base grows on its own.
LTV to CAC and Payback Period Calculator
Check whether a customer returns more gross profit than they cost to acquire.
Burn Multiple Calculator
Measure how many dollars you burn to add one dollar of net new ARR.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Churn Cost & Replacement Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/saas-churn-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/saas-churn-cost" target="_blank" rel="noopener">Churn Cost & Replacement Calculator — RevenueLab</a> (2026).</p>
Source: [Churn Cost & Replacement Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/saas-churn-cost) (2026).