LTV:CAC Ratio

The Critical LTV:CAC Ratio

The LTV:CAC ratio compares customer lifetime value, the total profit from a customer over the relationship, to customer acquisition cost, all sales and marketing expenses needed to acquire that customer. This ratio directly indicates marketing efficiency and business sustainability.

A 3:1 LTV:CAC ratio means each acquired customer generates three dollars of profit for every dollar spent acquiring them. This ratio predicts whether a SaaS company can scale profitably: higher ratios indicate strong unit economics, while lower ratios suggest unsustainable customer acquisition.

Calculating LTV and CAC

LTV = ARPU × Gross Margin × Customer Lifespan. Example: $100 monthly ARPU × 80% gross margin × 36 months average customer lifetime = $2,880 LTV.

CAC = Total Sales and Marketing Costs / Number of New Customers. Example: $10,000 monthly marketing spend plus $15,000 sales salary allocated to new customer acquisition, divided by 20 new customers, gives $1,250 CAC per customer.

Those two figures produce an LTV:CAC of $2,880 / $1,250, or 2.3:1.

Reading the Benchmarks

Use these reference points when interpreting the result:

• Healthy SaaS maintains a 3:1 to 5:1 LTV:CAC ratio.
• Below 3:1 indicates customer acquisition is expensive relative to customer value.
• Above 10:1 suggests potential underinvestment in growth.

Improving Ratio Through Affiliate Programs

Affiliates typically reduce CAC relative to paid advertising because commissions are performance-based. Affiliate-sourced customers cost 30-50% less to acquire than paid advertising cohorts.

Push the ratio higher on both sides of the equation:

• Recruit affiliates targeting high-LTV customer segments.
• Measure LTV by acquisition source, since affiliate-sourced customers may have higher LTV due to better product fit.
• Recruit affiliates whose audiences have demonstrated high customer quality.
• Focus recruitment on partners with highly engaged audiences, because quality followers drive higher conversion and lower churn.

Monitoring the Ratio Over Time

Monitor the LTV:CAC ratio by acquisition channel quarterly. If the affiliate channel achieves 4:1 while paid advertising achieves 2:1, allocate more budget to affiliate growth.

Also calculate cohort payback periods, meaning how long before the CAC investment returns revenue. Affiliate cohorts with sub-12-month payback periods are highly valuable for reinvestment.