LTV (Lifetime Value) shows how much value a customer brings over their entire lifetime. But first you need to decide what “value” means: revenue or gross profit. If the formula calculates revenue, you cannot later call the result profit. That will not put money in the register.
Updated August 11, 2026.
Revenue LTV and Gross Margin LTV
Revenue LTV measures revenue per customer. Gross margin LTV measures revenue after refunds, payment fees, cost of goods, and other variable costs.
The second metric is more useful for an ad budget. Buying a customer for 100 USD with revenue LTV of 120 USD can look like a great idea. If gross margin LTV is 70 USD, you are simply scaling a loss.
Historical LTV by Cohort
The most honest formula for data you have already accumulated is:
Revenue LTV on Day N = starting-cohort revenue through Day N / number of customers in the starting cohort.
For gross margin LTV, subtract refunds, fees, and variable costs from revenue first. This lets you compare LTV on D30, D90, D180, and beyond without pretending a young cohort has already lived its whole life.
If 1,000 customers generated 90,000 USD in revenue over their first 90 days, revenue LTV D90 is 90 USD. At a 70% gross margin, gross margin LTV D90 is 63 USD.
Simplified Subscription Formula
A stable subscription model often uses:
Revenue LTV = ARPU / customer churn.
If monthly ARPU is 30 USD and monthly customer churn is 5%, revenue LTV is 30 / 0.05 = 600 USD. At a 70% gross margin, gross margin LTV is roughly 420 USD.
This formula works only as a shortcut: the same period for ARPU and churn, stable churn, similar plans, and no abrupt product changes. Refunds, upgrades, downgrades, annual plans, discounts, seasonality, and volatile churn break the calculation fast.
LTV, CAC, and Payback
CAC is customer acquisition cost. LTV must be higher than CAC, but one ratio is not enough. If the money comes back in three years while the ad budget is needed today, the business can die with a beautiful LTV in the spreadsheet.
Payback period shows how many months it takes accumulated gross profit to repay CAC. Look at LTV, CAC, payback, and cash flow together. A universal rule such as LTV:CAC = 3:1 is convenient for a slide but does not replace the economics of a specific product.
Why a Media Buyer Needs LTV
For a media buyer, LTV answers a simple question: which traffic can you buy at a higher price and still make money? Calculate it by source, campaign, GEO, platform, creative, and launch cohort. Overall project LTV can easily mask a source with a good first payment and dead retention.
Do not compare the full LTV of an old cohort with the D30 LTV of a new one. Compare identical windows and identical maturity. Otherwise the winner will not be the better source but the one that had more time to accumulate money.
How to Increase LTV
- Reduce churn and get the customer to the first value.
- Increase ARPU through upgrades, cross-sell, and repeat purchases.
- Reduce refunds, fees, and variable costs.
- Remove fraud and traffic that never survives to monetization.
- Segment cohorts instead of treating the average as the patient.
Where LTV Lies
LTV remains a forecast until the cohort has lived its full lifetime. Old data describes a new product poorly, a few whales can pull the average up, and the overall metric hides differences between channels. The less data you have and the faster the business changes, the wider the margin for error should be.
LTV does not give you permission to spend anything you like. It gives you a ceiling that still has to be checked against margin, payback, and real cohorts.
See the other terms in the CPA glossary.