LTV in SaaS: How to Calculate Customer Lifetime Value

Customer lifetime value is one of the most quoted and most miscalculated numbers in SaaS. Done right, LTV in SaaS tells you how much a customer is truly worth over their entire relationship with you, which anchors how much you can afford to spend acquiring them. Done wrong, it produces a flattering number that leads you to overspend and wonder later why the cash never showed up.

This guide covers the correct lifetime value formula, why gross margin is the detail most people skip, the mistakes that inflate the number, and how LTV works alongside acquisition cost to tell you whether your growth is actually profitable.

What LTV Means in SaaS

LTV (customer lifetime value, sometimes written CLV or LTV) is the total gross profit you expect to earn from a customer across the whole time they stay subscribed. The two words that trip founders up are gross profit. LTV is not lifetime revenue — it is lifetime revenue after the cost of actually delivering the service. Skipping the margin adjustment is the single most common error, and it can overstate the number by a wide margin.

The reason the metric matters is that it puts a ceiling on acquisition spend. If a customer is worth $1,200 in gross profit over their lifetime, you cannot sustainably pay $1,500 to acquire them. LTV is the number that tells you where that line sits.

The LTV Formula

The standard SaaS lifetime value formula is:

LTV = (ARPA × Gross margin %) ÷ Customer churn rate

Breaking down each input:

• ARPAis average revenue per account per month — your total MRR divided by your number of accounts.
• Gross margin is the percentage of revenue left after the direct cost of serving customers (hosting, support, payment fees). For most SaaS this sits between 70% and 85%.
• Customer churn rateis the monthly percentage of customers who cancel. Its inverse (1 ÷ churn) is the average customer lifetime in months.

A worked example: if ARPA is $100/month, gross margin is 80%, and monthly churn is 2%, then LTV = ($100 × 0.80) ÷ 0.02 = $4,000. That $4,000 is the gross profit an average customer generates before they leave.

Why Churn Dominates LTV

Notice that churn sits in the denominator, which means small changes have an outsized effect. Using the example above, cutting monthly churn from 2% to 1% does not add a little to LTV — it doubles it, from $4,000 to $8,000. Nothing else in the formula has that kind of leverage.

This is why retention work pays for itself so quickly. Every point of churn you eliminate stretches the average lifetime and lifts LTV across your entire customer base at once. If churn is your bottleneck, our guide to understanding and measuring churn rate is the place to start, and improving net revenue retention is the compounding version of the same idea.

Accounting for Expansion Revenue

The basic formula assumes a customer pays the same amount every month. In reality, healthy SaaS customers often grow — adding seats, upgrading tiers, or buying add-ons. If your base expands over time, the simple formula understates LTV.

The cleaner approach is to use net revenue churn in the denominator instead of customer churn. When expansion outpaces cancellations, net revenue churn can be near zero or even negative, which sends LTV very high. That is the mathematical fingerprint of a business with strong expansion MRR — existing customers alone drive growth. Just be careful: a near-zero denominator produces a huge, unstable number, so treat those LTV figures as directional rather than precise.

Common LTV Mistakes

Because the formula is simple, it is easy to feed it bad inputs. The usual culprits:

• Using revenue instead of gross profit: the number one error. Always multiply by gross margin.
• Mixing monthly and annual figures: if ARPA is monthly, churn must be monthly too. Blending time periods breaks the math.
• Applying blended churn to different segments: enterprise customers churn far less than self-serve ones. A single blended rate hides that and distorts LTV for both.
• Ignoring the early-life cliff: many customers churn in the first 90 days. If early churn is high, the steady-state formula overstates the value of a fresh signup.

Segmenting LTV by Customer Type

A single blended LTV is almost always misleading, because different customer types behave nothing alike. Consider two segments of the same business:

• Self-serve:ARPA $40, 80% margin, 6% monthly churn. LTV = ($40 × 0.80) ÷ 0.06 = about $533.
• Enterprise:ARPA $900, 82% margin, 1% monthly churn. LTV = ($900 × 0.82) ÷ 0.01 = $73,800.

Blend those together and you get a number that describes neither segment and hides the fact that self-serve customers may barely be profitable after acquisition costs. Segmented LTV lets you set different acquisition budgets for each — a rule that becomes obvious once you see the two figures side by side. Whenever you can, calculate LTV per segment and per plan rather than for the company as a whole.

LTV and CAC: The Ratio That Matters

LTV means little in isolation. Its job is to be compared against what you spend to acquire a customer. The LTV:CAC ratiois the headline number investors look for, and around 3:1 is the healthy benchmark for most SaaS — each acquisition dollar returns three over the customer's lifetime.

Pair LTV with CAC payback periodtoo. A strong LTV:CAC ratio with a long payback means the lifetime economics work but cash comes back slowly — a real constraint when runway is tight. For the acquisition side of the equation, see how to measure CAC for SaaS by business model. Prefer to work directly from your Stripe data? Our walkthrough on calculating LTV from Stripe shows how to pull the real inputs.

Keeping LTV Accurate Over Time

LTV is not a set-and-forget number. ARPA drifts as you change pricing, churn moves as the product matures, and margins shift as you scale infrastructure. Recalculate it at least quarterly, and segment it so the enterprise and self-serve numbers stay separate.

Because every input — ARPA, churn, expansion — lives in your billing system, the reliable way to keep LTV current is to derive it straight from Stripe. StripeReport connects with a read-only key and tracks MRR, ARPA, churn, and expansion automatically, so the ingredients for your LTV calculation are always up to date and you are never working from a stale spreadsheet.

Key Takeaways

• LTV is lifetime gross profitper customer, not lifetime revenue — always apply gross margin.
• The formula is (ARPA × gross margin) ÷ churn; because churn is the denominator, small retention gains move LTV dramatically.
• Use net revenue churn to capture expansion, but treat very low denominators as directional.
• LTV only matters next to CAC — aim for roughly 3:1 and watch payback period for cash-flow reality.