What this calculator measures
The LTV:CAC ratio compares modeled lifetime customer value with acquisition cost. A ratio of 3.0 means the entered value is three times the entered acquisition cost. Both inputs inherit assumptions, so the ratio can look precise while remaining uncertain.
Use a margin-aware LTV and a consistently scoped CAC. Comparing lifetime revenue with fully loaded acquisition cost or profit LTV with media-only CAC can distort interpretation.
Common use cases
Use this model when the inputs describe the same decision, period and customer or product scope.
- Compare modeled customer lifetime value with acquisition cost and calculate value remaining after CAC.
- Use the result with the recorded inputs: Customer lifetime value, Customer acquisition cost.
- Compare multiple scenarios before making a marketing decision.
Formula
Read the ratio together with payback time, cash flow, retention, and the uncertainty in both inputs.
Formula breakdown
- LTV and CAC need compatible profit/revenue definitions and customer segments.
- Use comparable cohorts and time horizons.
Worked example
An LTV of $1,200 and CAC of $400 produce a 3.0:1 ratio. Modeled value after CAC is $800, and CAC represents 33.33% of LTV. That does not show when the $1,200 arrives or how much cash is required before payback.
Scenario comparison
$900 LTV and $300 CAC gives a 3.0x ratio.
If CAC rises to $450 with LTV unchanged, the ratio falls to 2.0x.
How to interpret the result
A higher ratio is not automatically ideal. An extremely high ratio may indicate room for additional efficient growth, while aggressive acquisition can create cash pressure even with favorable lifetime economics.
Review the ratio with CAC payback, retention, gross margin, cash runway, cohort quality, and channel scale. Sensitivity testing is valuable because small changes in lifespan can materially change LTV.
What a good result looks like
A higher ratio provides more economic headroom, but an extreme ratio can also signal under-investment in growth.
Use it together with payback and cash constraints.
Common mistakes
- Comparing gross-profit LTV with media-only CAC and calling it fully loaded economics.
- Treating immature LTV as realized value.
When this metric can mislead you
A strong ratio can hide a very long payback period.
Blended averages can hide unprofitable channels or segments.
How to use the result in a decision
Use it to compare acquisition channels and customer segments.
Inspect the underlying LTV and CAC whenever the ratio changes.
Assumptions and limitations
- LTV and CAC use compatible customer, margin, and channel definitions.
- Both values are measured in the same currency.
- CAC is greater than zero.
- Timing, risk, and uncertainty are not represented by the ratio.