App CAC Calculator
Ad spend and CPI in → cost per subscriber, LTV:CAC ratio and breakeven CPI out. The three numbers that decide whether your campaigns deserve more budget.
FAQ
What is a good LTV to CAC ratio for apps?
3:1 is the classic healthy benchmark — every $1 of acquisition returns $3 of lifetime value. Between 1.5:1 and 3:1 is workable while you optimize; below 1:1 you lose money on every subscriber and need to fix the funnel, the paywall or the price before scaling spend.
How do I calculate CAC for a subscription app?
CAC per subscriber = total ad spend ÷ new subscribers from that spend. With a $1.20 CPI and a 3% paywall conversion, one subscriber needs ~33 installs, so CAC ≈ $40. That's why paywall conversion matters as much as cheap installs.
What is breakeven CPI?
The highest cost-per-install at which ads still pay for themselves: LTV × paywall conversion. If your LTV is $21 and conversion is 3%, any CPI under $0.63 is profitable. It's the single most useful bid ceiling for Meta and TikTok campaigns.