Customer Lifetime Value (LTV)

What LTV Tells You

Customer Lifetime Value answers one question: how much is a customer actually worth? It is the single number that lets you decide how much you can afford to spend acquiring them, and it is the metric that separates businesses with real unit economics from businesses burning cash on growth that never pays back.

For an early-stage founder, LTV matters because it is the denominator (or partner metric) in almost every important decision you will make: pricing, paid acquisition budgets, retention investment, and fundraising narrative. Investors do not just want to see revenue growth, they want to see that each customer is worth meaningfully more than it costs to acquire them.

The Basic Formula

The simplest version of LTV for a subscription business is:

LTV = Average Revenue Per Account (ARPA) x Gross Margin % x Customer Lifetime (in months)

Where customer lifetime is typically calculated as:

Customer Lifetime = 1 / Monthly Churn Rate

Worked Example

Say your SaaS product charges $50/month per customer, your gross margin is 80%, and your monthly churn rate is 5%.

1. Customer Lifetime = 1 / 0.05 = 20 months
2. LTV = $50 x 0.80 x 20 = $800

That $800 is the ceiling, in theory, on what you can profitably spend to acquire that customer. If your Customer Acquisition Cost (CAC) is $200, you have a healthy 4:1 LTV:CAC ratio. If your CAC is $700, you are barely breaking even, and you have almost no room for the payback period, support costs, or churn to get worse.

Why Churn Dominates the Calculation

Churn rate is the most sensitive input in the LTV formula, because it compounds. Cutting monthly churn from 5% to 2.5% does not just improve retention modestly, it doubles the customer lifetime (from 20 months to 40 months) and therefore doubles LTV, with no change to pricing or acquisition spend at all.

This is why experienced operators obsess over churn before they obsess over growth. A leaky bucket makes every other lever, including LTV, look worse than it should.

Benchmarks: What's a Good LTV?

LTV on its own is meaningless without context. It only becomes useful when compared to CAC, expressed as the LTV:CAC ratio.

• Below 1:1: You lose money on every customer. Unsustainable without a plan to fix it.
• 1:1 to 3:1: Marginal. You may be growing, but margins are thin and there's little room for error.
• 3:1: The commonly cited healthy benchmark for SaaS businesses.
• 5:1 or higher: Strong unit economics, though very high ratios can also signal you're underinvesting in growth and leaving acquisition budget on the table.

These benchmarks vary by business model. Marketplaces, hardware, and low-margin ecommerce businesses often run on very different ratios than SaaS.

Common Mistakes Founders Make

Using revenue instead of gross margin. LTV should reflect profit contribution, not top-line revenue. Ignoring cost of goods sold, hosting, support, and payment processing inflates the number and leads to overspending on acquisition.

Averaging across very different customer segments. A blended LTV can hide the fact that your enterprise customers are worth 10x your self-serve customers. Segment LTV by acquisition channel, plan tier, or cohort whenever you have enough data.

Calculating LTV too early with too little data. If you have three months of retention data, any churn-based lifetime projection is a guess dressed up as a formula. Early on, it is often more honest to talk about early cohort retention curves than to publish a precise LTV number.

Ignoring expansion revenue. For product-led or usage-based businesses, upsells and expansion can dramatically change LTV. A more complete formula accounts for net revenue retention, not just the original subscription price.

Treating LTV as static. It should be recalculated regularly as pricing, churn, and margins shift, especially right after a pricing change or a new onboarding flow ships.

How to Use LTV Day to Day

Rather than treating LTV as a vanity metric for a pitch deck, use it operationally:

• Set paid acquisition budgets based on LTV:CAC, not gut feel.
• Prioritize retention work when churn is the binding constraint on LTV (it almost always is, early on).
• Segment LTV by channel to decide where to double down on marketing spend.
• Track LTV alongside CAC payback period, since a great LTV:CAC ratio with a 24-month payback can still starve a startup of cash.

Getting LTV right early, even roughly, gives founders a much clearer view of whether the business model works before scaling spend. Tools like welaunch.sh can help founders track these metrics from day one instead of retrofitting them after a launch.