What is the LTV:CAC ratio?
The LTV to CAC ratio compares what a customer is worth to what they cost to acquire. A 3 to 1 ratio means each customer returns three dollars of lifetime gross profit for every dollar spent winning them.
It is the single clearest read on whether a SaaS growth model works. One number tells you if acquisition is building value or burning it.
The LTV:CAC formula.
LTV:CAC = lifetime value divided by customer acquisition cost. Use gross-profit LTV, not revenue LTV, so the ratio reflects what you keep. If you are not sure of either input, the LTV calculator and the CAC calculator work them out first.
A worked example.
A customer is worth 20,000 dollars in lifetime gross profit and costs 5,000 dollars to acquire. The ratio is 20,000 divided by 5,000, which is 4 to 1.
What is a good LTV:CAC ratio?
3 to 1 is the benchmark most B2B SaaS boards expect. The bands are well established. Below 1 to 1, you spend more to acquire a customer than they ever return, and growth destroys value. Between 1 and 3, the model works but margins are thin. Between 3 and 5 is healthy, and the economics support spending more on growth. Above 5 to 1 is efficient, but often a sign you are under-investing and could grow faster by spending more.
The ratio is a starting point, not the whole story. A 3 to 1 ratio with a 30-month payback is weaker than a 3 to 1 ratio that pays back in 8, because cash matters. Read the ratio alongside CAC payback.
How to improve your LTV:CAC.
Two levers. Raise LTV through retention, expansion, or pricing. Lower CAC through better conversion or a cheaper channel mix. Most teams reach for paid spend to grow, which raises CAC and pushes the ratio down.
The move that improves both sides is a compounding channel. Organic search lowers blended CAC and brings better-qualified customers who churn less, which lifts LTV. See how we improve SaaS unit economics with organic search.