Customer Lifetime Value: How to Calculate CLV, Including Margin and Discounting

Customer lifetime value is the total profit a customer generates over the whole relationship. The version most teams calculate — revenue per month times an assumed lifespan — overstates it, often by a factor of two or more.

Three adjustments separate a marketing CLV from one a CFO or an acquirer will accept: gross margin instead of revenue, lifespan derived from churn rather than assumed, and future cash discounted to present value. This covers all three, plus when a cohort figure tells you something the blended number hides.

What is customer lifetime value?

Customer lifetime value is the total profit attributable to a customer across their entire relationship with the business.

It exists to answer one question: how much can you afford to spend acquiring a customer? Every other use — segment prioritization, retention investment, valuation — is downstream of that. CLV and CAC are only meaningful as a pair.

The simple CLV formula, and where it breaks

The common version:

CLV = Average purchase value × Purchase frequency × Customer lifespan


For a subscription business this simplifies to monthly recurring revenue times lifespan in months. A customer paying $850 a month for an assumed 36 months gives a CLV of $30,600.

That figure is wrong in three specific ways.

It counts revenue, not profit. The business does not keep $850. After hosting, support and the cost of serving the account, it might keep $660.

The lifespan is assumed. Thirty-six months is a guess unless it came from churn data, and guesses in this position tend upward.

It ignores the time value of money. A dollar arriving in month 34 is not worth a dollar today, particularly for a business raising capital at a meaningful cost.

Each has a fix.

Gross-margin CLV

The first correction, and the one that matters most.

CLV = (Monthly revenue per customer × Gross margin %) × Lifespan in months


With 78% gross margin, the same customer:

(850 × 0.78) × 36 = 663 × 36 = $23,868

Down from $30,600. A 22% reduction, from one adjustment.

Use gross margin, not net. Gross margin captures the cost of delivering the service — infrastructure, support, third-party fees, customer success. It excludes sales, marketing and overhead, which belong in CAC and in the P&L respectively. Putting them in CLV double-counts them against the same customer.

Deriving customer lifespan from churn

The second correction replaces the assumption.

Average lifespan = 1 ÷ Churn rate


The periods must match. Monthly churn gives lifespan in months; annual churn gives years. Mixing them produces errors of a factor of twelve, and it happens more often than it should.

At 2.4% monthly churn:

1 ÷ 0.024 = 41.7 months

So the assumed 36 was conservative here, and the CLV rises:

663 × 41.7 = $27,647

Two cautions.

At low churn the formula becomes unstable. At 0.5% monthly it returns a 200-month lifespan — nearly 17 years — which no SaaS business should put in a model. Cap the lifespan at something defensible, commonly 36 to 60 months, and say that you have. Our SaaS LTV calculator applies the margin and churn adjustments described here if you want a working figure before rebuilding the model properly.

And churn is rarely flat. Most businesses lose a disproportionate share of customers in the first three months, after which the survivors churn far more slowly. A single blended rate applied to everyone underestimates the value of customers who survive onboarding and overestimates the value of new ones.

Discounted CLV: what a CFO or acquirer expects

The third correction, and the one that is routinely skipped. Wall Street Prep's 2024 treatment raises discounting and then sets it aside for simplicity; HubSpot's guide omits it. In diligence, it is the first thing rebuilt.

Money arriving in the future is worth less than money today. Discounted CLV values each month's contribution at present value:

CLV = Σ [ Monthly gross profit ÷ (1 + r)^n ]


Where r is the monthly discount rate and n the month.

Using $663 monthly gross profit, a 41.7-month lifespan and a 12% annual discount rate — roughly 0.95% monthly:

PeriodUndiscountedDiscountedMonths 1–12$7,956$7,486Months 13–24$7,956$6,683Months 25–36$7,956$5,966Months 37–41.7$3,779$2,604Total$27,647$22,739

Roughly $22,700 against $27,600 — an 18% reduction, and it compounds with the margin adjustment made earlier.

Follow the whole chain from the starting figure:

MethodCLVRevenue × assumed 36-month lifespan$30,600Gross-margin adjusted$23,868Lifespan from churn (41.7 months)$27,647Discounted to present value$22,739

Same customer, same business. The first number is 35% higher than the last.

Which discount rate to use is a judgment call. Weighted average cost of capital is the formal answer. In practice many SaaS models use 10–15%, and the specific figure matters less than stating it.

Cohort CLV vs blended CLV

A blended CLV averages every customer the business has ever signed. That average is dominated by whichever cohort was largest, which is usually the oldest.

Cohort CLV groups customers by when they were acquired, or by segment, and calculates each separately.

Consider a business whose blended CLV is $22,739. Split by acquisition channel:

CohortGross margin CLVShare of customersReferral$41,20014%Organic search$26,40038%Paid social$11,90048%

The blended figure describes none of them. It suggests healthy unit economics while nearly half the customer base is worth roughly half the average — and if paid social also carries the highest CAC, that segment may be unprofitable inside a business that looks fine in aggregate.

This is the practical argument for cohorts: a blended CLV can only tell you whether the business works on average. Decisions are made per channel and per segment, and those need CLV calculated the same way.

LTV:CAC — what it tells you and what it hides

The ratio compares what a customer is worth against what they cost to acquire. Three to one is the standard target.

It is a useful summary and a poor sole instrument, for two reasons. It inherits every assumption in the CLV above it, so a 3:1 built on an undiscounted revenue-based CLV may really be closer to 2:1. And it says nothing about timing — a healthy ratio with a two-year payback can still be a cash crisis.

We have covered the ratio, payback period and what belongs in the denominator in how to calculate customer acquisition cost.

A worked correction: how a CLV loses a third of its value

The following is a modeled scenario built from the methods above, not a client account. The figures are illustrative.

A subscription business reports CLV of $30,600 and uses it to justify a $7,000 CAC — a comfortable-looking 4.4:1 ratio.

That figure is monthly revenue of $850 multiplied by an assumed 36-month life. Applying the three corrections in order:

StepMethodCLVRatio at $7,000 CACReportedRevenue × assumed 36 months$30,6004.4:1Gross margin at 78%Profit, not revenue$23,8683.4:1Lifespan from 2.4% monthly churn41.7 months, measured not assumed$27,6473.9:1Discounted at 12% annualPresent value$22,7393.2:1

Note that the second correction raised the figure — measured churn gave a longer life than the assumption did. That is common, and it is why teams resist the exercise less than expected once they start it.

The ratio ends at 3.2:1 rather than 4.4:1. Still above the 3:1 threshold, but with far less room: a 10% rise in acquisition cost, or half a point of monthly churn, puts it under.

The practical consequence is not the number but the decision it supports. At 4.4:1 a business will approve an increase in acquisition spend without much scrutiny. At 3.2:1 the same proposal needs a view on churn first — which is the right order to think in.

What to do with the number

Rebuild CLV with gross margin rather than revenue, derive lifespan from your actual churn rate, and cap it at something you can defend. Then split it by acquisition channel, because the blended figure is the one least likely to inform a decision.

If your CLV has never been discounted, expect it to fall by 15–20% the first time someone in diligence rebuilds it. That matters well beyond reporting: lifetime value and acquisition efficiency are two of the inputs buyers price directly, as we set out in how to increase your SaaS valuation multiples before an exit.