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Business & Tax
How lifetime value is actually calculated, why the naive version overstates it, and what the number is allowed to justify.
By FreeCalculators Editorial · Published 2026-09-01 · Updated 2026-09-04 · 4 min read · 931 words
Customer lifetime value is the total gross profit a customer generates over the whole relationship, discounted back to what it is worth today. It matters because it sets the hard ceiling on acquisition spend: no channel, campaign or discount can be justified if it costs more to win a customer than that customer will ever contribute. Almost every version quoted in practice overstates it, and the overstatement is where growth budgets go to die.
The simple form is average revenue per period, multiplied by gross margin, multiplied by the expected number of periods retained. Two corrections separate a usable number from a flattering one. First, use gross profit rather than revenue, because revenue you must spend to deliver is not value. Second, discount future periods, because a dollar of margin five years out is not worth a dollar today.
A third correction applies to subscription businesses: expansion revenue from existing customers raises lifetime value, but only if net revenue retention is genuinely above 100% across the whole cohort rather than in your best accounts.
| Version | Basis | Result on the worked example | Why it differs |
|---|---|---|---|
| Naive | Revenue x months | $3,600 | Counts money you spend to deliver |
| Margin-adjusted | Gross profit x months | $2,520 | Removes cost of delivery |
| Discounted | Gross profit, present value | $2,180 | Future margin is worth less today |
| With churn drift | Rising churn in later months | $1,910 | Retention curves flatten, then fall |
Average retention is computed from customers who have already churned, so it systematically excludes the ones still to leave. New businesses see this most sharply: with two years of history you cannot observe a five-year lifetime, and assuming one is a forecast dressed up as a measurement. The honest approach is to cap the horizon at a period you have actually observed, then say so.
Lifetime value, calculated properly (2026)
Inputs Monthly revenue per customer $150 Gross margin 70% Monthly gross profit 150 x 0.70 $105 Monthly churn 4.0% Expected months 1 / 0.04 25 Discount rate (annual) 10% Naive 150 x 25 $3,750 Margin-adjusted 105 x 25 $2,625 Discounted at 10% annual over 25 months approx. $2,270 Acquisition ceiling at a 3x target 2,270 / 3 $757
The naive figure would have justified spending $1,250 to win that customer at the same 3x target. The corrected figure caps it at $757. That difference of nearly $500 per customer is the gap between a channel that scales and one that quietly consumes the business.
Lifetime value sets the acquisition ceiling, ranks segments for sales focus, and tells you whether a retention investment pays. It does not by itself justify a channel, because payback period matters independently: a customer worth $2,270 over 25 months does not fund a $757 acquisition cost today unless you can finance the gap. The Small Business Administration is explicit that undercapitalisation, not lack of demand, is among the most common causes of small-business failure, and paying for lifetime value out of this month's cash is exactly that failure mode.
Treat lifetime value as the ceiling and payback period as the constraint. Both have to clear before a channel is genuinely working.
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This guide was written and reviewed by FreeCalculators Editorial, drawing on published formulas, official government sources, and real calculator outputs from our 4 calculators in this category. Every claim is sourced; every formula is auditable. Read our review policy.