Your breakeven CAC is the floor. Repeat purchases raise the ceiling. Enter your numbers to see customer lifetime value, your LTV:CAC ratio, and how long it takes to earn back what you spend acquiring a customer.
Gross-margin economics for a repeat-purchase business.
The total gross profit one customer brings over their lifetime.
A 3:1 ratio is sometimes used as a general reference, but the right target depends on margin, cash position, retention, growth stage and business model. Allowable CAC at that 3:1 reference: —.
Months of gross profit to earn back CAC. Shorter means less cash tied up.
—
Honest caveat: this is a gross-margin LTV, and it's only as good as your retention inputs — lifespan, churn, or repeat rate — which most businesses estimate rather than measure. Treat the result as a modelled ceiling, not a fact, until you can pull real cohort retention. The 3:1 reference is a rule of thumb, not a law: a cash-tight startup may need faster payback, while a high-margin, low-churn business can justify going lower. Getting that retention measurement right is the foundation work we do first.
LTV is only as trustworthy as the retention data behind it. A free foundation audit checks whether your analytics can actually measure repeat purchases and cohort retention — before you bet a higher CAC on a number you can't see.
Request a free audit