App install CPI break-even calculator
Find out whether your install cost is recoverable — and what CPI you can afford at your current retention and ARPU.
Enter your CPI, Day 30 retention rate, monthly ARPU, and platform commission. The calculator shows your payback period and the maximum CPI that keeps you profitable at 3, 6, and 12-month targets.
CPI break-even calculator inputs and results
How this calculator works
Monthly net revenue per install = Day 30 retention rate × net ARPU. Of every 100 installs, only those still active at Day 30 contribute ongoing revenue — the rest churned before then. Payback period is CPI divided by this monthly net revenue per install.
The max affordable CPI at a target payback is monthly net revenue per install multiplied by the target months. At 6-month payback and $0.63 monthly revenue per install, the max CPI is $3.78 — any higher and you won't recover the install cost within 6 months at current metrics.
This is a simplified model that treats monthly revenue per install as constant after D30. In practice, revenue per retained user grows with engagement depth and declines gradually with retention decay — but for planning UA budget allocation, this approximation is accurate enough for most decisions.
About this tool
This tool calculates whether a UA campaign's cost per install is recoverable from in-app revenue, and how long it takes. Inputs: cost per install (CPI), Day 30 retention rate (%), average monthly revenue per retained user (ARPU), and platform commission (%). Outputs: monthly net revenue per install, payback period in months, and the maximum CPI affordable at 3, 6, and 12-month payback targets. Useful for evaluating UA channel efficiency before scaling spend.
Frequently asked questions
What does "Day 30 retention" mean here?
Day 30 retention is the percentage of users who are still active 30 days after installing your app. It represents the share of an install cohort that remains engaged enough to generate ongoing revenue. The model uses D30 retention as a proxy for the long-term retained user base — users who drop off before Day 30 are assumed to generate negligible revenue. In practice, revenue accrues throughout the first 30 days too, but D30 retention gives a reasonable steady-state approximation.
What should I use for monthly ARPU?
Use the average monthly revenue per retained active user — what a Day 30+ user typically contributes per month, averaged across paying and non-paying users. For a subscription app, this is the monthly price multiplied by the paid conversion rate of retained users. For an ad-supported app, it's average ad revenue per DAU. For a freemium app with IAP, it's total monthly IAP revenue divided by monthly active users. Use net ARPU after platform commission, or enter your gross ARPU and set the commission to your actual rate.
Why is D30 retention used instead of a full retention curve?
D30 retention is the most commonly tracked cohort metric and provides a useful proxy without requiring a full retention model. The approximation assumes users who are retained at Day 30 continue contributing revenue at roughly their average rate. For a more accurate analysis, you'd model the full retention curve and weight ARPU at each time step — but for a planning tool, D30 captures enough of the signal for most decisions.
How does platform commission affect break-even?
Platform commission reduces your effective ARPU by your revenue share. At 30% commission, $5 gross ARPU becomes $3.50 net. This directly extends your payback period — the higher the platform cut, the longer it takes to recover a given CPI. Qualifying for the 15% small developer rate effectively reduces your payback period by around 21% at the same gross ARPU, which can be the difference between a viable and unviable UA channel.