Ratio = CLTV ÷ CLM
In the standard construction both apply gross margin to lifetime revenue, so the answer is 1.0.
That is not a useless result. A ratio away from 1.0 tells you the two were built on different assumptions, and it is often the first sign that a reporting pack contains two incompatible views of the same customer.
Why they can diverge
- Different margin definitions. One applies gross margin, the other applies
contribution margin after support.
- Different churn. One uses logo churn, the other revenue churn.
- Different horizons. One capped, one not, which is the largest and most
common source of divergence.
- Different segment mixes.
The last is the subtle one: a blended CLTV against a segment-specific CLM will never reconcile, and neither number is wrong.
What to do with a divergence
Reconcile before either figure informs a decision. In practice the horizon is usually the culprit, and capping both at the same number of years resolves it.
If your organisation genuinely uses CLTV and CLM to mean different things, write the definitions down once. The confusion is caused by the labels, not the arithmetic. See customer lifetime margin for the family and what each subtracts.
The traps
- Reporting it as a performance metric. It is a diagnostic.
- Assuming a divergence is an error rather than a definition difference.
- Publishing both CLTV and CLM without saying how they differ.
Where this sits
Measurement in the Tenbound Pipeline Architecture Standard, as a reconciliation check rather than an operating number.