Last updated: June 2026·by mrrsucks.com

Unit Economics

Customer Lifetime Value (LTV)

LTV

Customer Lifetime Value (LTV, also CLV) is the total net revenue a business expects to receive from a customer over the entire duration of their relationship. It is the foundational unit economics metric — every customer acquisition decision, pricing choice, and retention investment should be evaluated against LTV. A higher LTV justifies higher CAC, longer payback periods, and more aggressive retention investment.

formula.sh

LTV = ARPU × Gross Margin % × (1 / Monthly Churn Rate)

> ARPU — Average Revenue Per User (monthly)
> Gross Margin % — the percentage of revenue retained after direct costs (hosting, support, etc.)
> 1 / Monthly Churn Rate — the average customer lifetime in months (e.g., 2% churn = 50 months lifetime)
> For businesses with expansion revenue, use a more complex model: LTV = (ARPU × Gross Margin) / (Churn Rate − Expansion Rate)

example

example.sh

SaaS with $120/month ARPU, 75% gross margin, and 2% monthly churn rate.

$120 × 0.75 × (1 / 0.02)

→ $4,500 LTV — the average customer is worth $4,500 in gross profit over their lifetime with you.

why it matters

LTV determines the maximum rational spend on customer acquisition. The famous rule of thumb — LTV should be at least 3x CAC — exists because you need margin above and beyond the acquisition cost to cover operational overhead, payback period financing costs, and profit. If LTV is $4,500 and CAC is $3,000, you are likely destroying value even though the ratio exceeds 1.

LTV is also the lens through which retention investments should be evaluated. If improving onboarding reduces monthly churn from 3% to 2%, LTV increases from $3,000 to $4,500 (a 50% increase). Every $1 spent on customer success that reduces churn generates multiplicative LTV improvement — it does not just save one customer, it permanently extends the lifetime of all future customers in that cohort.

The biggest LTV mistake is treating it as static. LTV should be modeled dynamically using actual cohort curves, not a simplified formula. Companies with improving product-market fit will see LTV increase over time as newer cohorts retain better and expand more.

common mistakes

✗Using revenue LTV instead of gross margin LTV — you must subtract variable costs to understand what a customer is actually worth to your business.

✗Applying a single LTV to all customers — high-tier and low-tier customers, and different acquisition channels, have dramatically different LTV profiles.

✗Using a simplified formula without accounting for expansion revenue — in a product with strong NRR, LTV can be 2–5x higher than the simple formula implies.

pro tips

✓Calculate LTV by cohort using actual survival curves rather than the simple formula — cohort data shows the real shape of customer lifetime, which is often non-linear.

✓Model LTV sensitivity to churn: a 1% improvement in monthly churn rate often increases LTV by 30–50%. Show this to your board as the ROI case for customer success investment.

✓For fundraising, show LTV expansion over time by vintage — if newer cohorts have higher LTV due to product improvements, that is a powerful growth narrative.

the mrrsucks take

LTV without gross margin is vanity. LTV without a payback period context is fiction. And LTV calculated without actual cohort data is the number you wanted to believe, not the number that exists.

faq

What is a good LTV/CAC ratio?+

The benchmark is 3:1 or higher. Below 3:1, you are likely destroying unit economics even if growing. Above 5:1 often means you are underinvesting in acquisition and leaving growth on the table. The target zone is 3–5:1 for most SaaS businesses.

How do I increase LTV?+

Four levers: reduce churn (extends lifetime), increase ARPU through pricing optimization or upsells (increases revenue per period), improve gross margin (increases the value of each revenue dollar), and create expansion pathways (adds revenue per customer beyond initial plan).

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