What is a good LTV to CAC ratio?
LTV:CAC compares the gross profit a customer generates over their lifetime to what it cost to acquire them. Around 3:1 is the common benchmark — below 1:1 you lose money on every customer, and far above 3:1 usually means you are underspending on growth rather than winning. The ratio is only as honest as the retention assumption inside LTV.
The calculation, and the part everyone fudges
CAC is total sales and marketing spend in a period divided by new customers acquired in that period. Include salaries, not just ad spend — a team of five running content is a real acquisition cost.
LTV is average gross profit per customer per period, divided by the churn rate for that period. The division is where the fiction enters. If you have twelve months of data and you divide by a 2% monthly churn rate, you are asserting the average customer stays fifty months — thirty-eight months longer than your product has existed. Early-stage LTV is a projection wearing the costume of a measurement.
Why 3:1
It is a heuristic, not a law. The logic: at 1:1 you have exactly recovered acquisition cost and funded none of the engineering, overhead or support that made the product exist. Roughly three times gives room for those costs plus margin. Below about 1.5:1 most businesses cannot grow without continuously raising money to fund the gap.
MoviePass is the cautionary version. Ten dollars a month against customers who saw several twenty-dollar films made the ratio permanently negative, and volume made it worse rather than better — every new subscriber deepened the loss. No amount of growth fixes an inverted ratio, because growth is the thing multiplying it.
Ratios lie in three specific ways
Blended CAC hides a broken channel. Averaging cheap organic signups with expensive paid ones produces a comfortable number that conceals a paid channel losing money. Segment by channel or the ratio tells you nothing you can act on.
Cohort effects get averaged away. Your first customers were enthusiasts who retained well. Later cohorts, acquired through broader channels, often churn faster. A blended LTV built on early cohorts overstates every customer you will acquire next year.
A pandemic or a spike gets extrapolated. Peloton read an extraordinary demand surge as the new baseline, which flattered every forward-looking unit economic it had. The ratio was accurate about a moment and wrong about the future.
Using it well
Compute it by channel and by cohort, use gross profit, and pair it with payback period. Then treat the number as a decision aid for how much to spend, not as a score. The ratio's real job is answering one question — should we put more money into this channel — and it answers that well as long as you refuse to average away the segments where the answer is no.
Seen in practice
Case studies where this shows up as a real decision, not a definition.
Related questions
Should LTV use revenue or gross profit?
Gross profit. Using revenue ignores the cost of serving the customer, which for anything with delivery, hardware, support or heavy infrastructure is the majority of the money. A revenue-based LTV:CAC of 4:1 can be a loss-making business once cost of goods is subtracted.
Is a 10:1 LTV to CAC ratio good?
Usually it means you are leaving growth on the table. A very high ratio says acquisition is cheap relative to value, and the rational response is to spend more until the ratio compresses toward 3:1. The exception is a company deliberately conserving cash.
How long should CAC payback take?
Twelve months is the usual target for B2B SaaS, shorter for consumer. Payback period matters more than the ratio when cash is tight, because a 3:1 ratio with a 30-month payback still means you fund every customer for two and a half years before you see the money.
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Last reviewed 2026-09-08