The LTV:CAC ratio is the single number that tells you whether paying for growth makes sense: how many times the profit from a customer covers the cost of winning them. Below 1:1 you lose money on every sign-up; around 3:1 is the widely used healthy benchmark; above 5:1 you are probably under-investing. Enter your lifetime value and acquisition cost for the ratio and a verdict, and the monthly gross profit per customer to see how many months it takes to earn the acquisition cost back.
LTV:CAC Ratio Calculator
The ratio of customer lifetime value to customer acquisition cost is the quickest health check for any business that pays to win customers. The LTV:CAC calculator divides one by the other and gives a plain-language verdict: a customer worth $960 in gross profit who costs $300 to acquire is a 3.2:1 ratio, comfortably in the healthy 3:1 to 5:1 band.
Below 1:1 every new customer destroys value; between 1:1 and 3:1 the business works but has little room for error; above 5:1 investors usually read it as a sign you could spend more on growth. Enter the gross profit a customer brings each month and the calculator adds the payback period, the number of months before an acquisition pays for itself, which matters as much as the ratio when cash is tight. Work out the inputs with the LTV and CAC calculators.
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Frequently Asked Questions
Why is 3:1 the benchmark?
At 3:1 a customer generates three times what they cost to acquire, which leaves room for the costs of serving them, for churn that comes earlier than expected and for a profit. It is a rule of thumb from SaaS investing, not a law; capital-light businesses can accept less, slow-payback businesses need more.
What is CAC payback?
The number of months of gross profit needed to recover the acquisition cost. Under 12 months is comfortable for most businesses; venture-funded SaaS companies often tolerate 12–24 months.
My ratio is above 5:1. Is that bad?
It usually means you could win more customers profitably by spending more on acquisition, or that your LTV assumptions are optimistic. Check the lifespan and margin behind the LTV before scaling the budget.
