What is the LTV to CAC ratio?

The LTV:CAC ratio compares the value a customer generates over their relationship with a business with the cost required to acquire that customer. Divide LTV by CAC to calculate it.

How do I calculate LTV:CAC?

Divide customer lifetime value by customer acquisition cost. For example, an LTV of $900 and CAC of $300 gives 900 ÷ 300 = 3, usually written as 3:1.

Is a 3:1 LTV:CAC ratio always good?

No universal ratio is good for every business. A 3:1 ratio is a useful illustration, but acceptable economics depend on gross margin, cash flow, payback period, retention, operating costs, growth goals, and how consistently LTV and CAC are measured.

Can LTV:CAC be high while the business loses money?

Yes. A high ratio can still be misleading if LTV is based on revenue rather than contribution profit, retention assumptions are too optimistic, overhead is substantial, or acquisition costs are incomplete.

Should I calculate LTV:CAC by marketing channel?

When reliable attribution is available, channel or cohort calculations can be more useful than a blended company-wide ratio because acquisition cost and customer quality can differ substantially by source.

How to Calculate LTV:CAC Ratio

The LTV:CAC ratio compares customer lifetime value with customer acquisition cost. It is a compact way to examine unit economics, but it is only useful when both inputs are calculated consistently. This guide explains the formula, a worked example, interpretation, and common mistakes.

Last reviewed: 2026-09-14

LTV:CAC ratio formula

LTV:CAC Ratio = Customer Lifetime Value ÷ Customer Acquisition Cost

If customer lifetime value is $900 and customer acquisition cost is $300, the ratio is 3.0, commonly written as 3:1. That means the measured lifetime value is three times the measured acquisition cost. Before using the ratio, calculate the two inputs separately with the LTV Calculator and CAC Calculator.

Worked LTV:CAC example

Suppose a subscription business estimates that an average customer contributes $50 per month after the variable costs included in its LTV model and remains active for an average of 18 months. The business spends $60,000 on acquisition during the period and acquires 400 new customers.

LTV = $50 × 18 = $900
CAC = $60,000 ÷ 400 = $150
LTV:CAC = $900 ÷ $150 = 6.0 = 6:1

On those assumptions, estimated lifetime value is six times acquisition cost. The ratio does not mean the business earns $6 of immediate cash for every $1 spent. LTV unfolds over time, while acquisition spending may be paid before much of that value is collected.

How to interpret the ratio

A ratio below 1:1 means measured acquisition cost exceeds measured lifetime value. A ratio above 1:1 means measured lifetime value exceeds acquisition cost, but that alone does not guarantee overall profitability. Payroll, software, rent, financing, taxes, refunds and other operating costs may sit outside the calculation.

You may see 3:1 described as a general benchmark online. Treat it as a reference point, not a rule. A capital-efficient software business, a low-margin retailer and a rapidly growing marketplace can rationally operate with different targets. The useful benchmark is the one derived from your margins, cash requirements, retention and growth objectives.

Use consistent definitions of LTV and CAC

The numerator and denominator must describe compatible customer groups and time periods. If LTV is contribution-profit based, keep that definition consistent when comparing cohorts. For CAC, include the acquisition costs required by your chosen methodology rather than only media spend. Read how to calculate LTV and how to calculate CAC before relying on the combined ratio.

Revenue LTV vs contribution-based LTV

Revenue-based LTV can make the ratio look stronger because revenue is not profit. For example, $1,000 of lifetime revenue with a 40% contribution margin represents $400 of contribution before acquisition cost and other excluded expenses. Against a $200 CAC, revenue LTV produces a 5:1 ratio, while contribution-based LTV produces 2:1.

Revenue LTV:CAC = $1,000 ÷ $200 = 5:1
Contribution LTV = $1,000 × 40% = $400
Contribution LTV:CAC = $400 ÷ $200 = 2:1

Blended vs channel-level LTV:CAC

A blended ratio combines customers and acquisition spending across sources. It is useful for a broad view but can hide large differences. Paid search might acquire expensive, high-retention customers while a referral program acquires cheaper customers with different behavior. When attribution and sample sizes are reliable, compare cohorts or channels using the same LTV and CAC definitions.

Do not ignore CAC payback period

Two businesses can have the same LTV:CAC ratio but very different cash profiles. If one recovers its acquisition cost in three months and another needs eighteen months, the second generally requires more working capital to support the same growth rate. LTV:CAC describes the size of expected lifetime value relative to acquisition cost; payback describes how quickly acquisition spending is recovered.

Common LTV:CAC mistakes

The most common errors are mixing revenue-based and profit-based LTV, omitting acquisition expenses from CAC, comparing different customer cohorts, using overly optimistic lifetime assumptions, and treating a generic benchmark as a universal target. Recalculate the ratio when pricing, margins, retention, channel mix or acquisition costs change materially.

Practical takeaway

Calculate LTV and CAC with explicit, consistent assumptions, then divide LTV by CAC. Use the resulting ratio as one unit-economics signal alongside contribution margin, retention, cash flow and CAC payback. The ratio becomes most useful when tracked consistently over time and compared across meaningful customer cohorts rather than viewed as a standalone score.