Customer Lifetime Value (LTV) is the total revenue your startup expects to earn from a single customer over the entire period they remain active or engaged with your product.
LTV is a critical metric for startups because it shows the long-term value of acquiring a customer. Knowing LTV allows you to make informed decisions about marketing spend, pricing, and growth strategies.
LTV = Average Revenue per User (ARPU) × Average Customer Lifetime
It represents how much revenue one customer brings during their “lifetime” with your business.
For example, if an average customer spends $20 per month for 12 months:
LTV helps answer key strategic questions:
LTV is especially important for subscription businesses, SaaS, marketplaces, and any model where customers make repeat purchases.
Simple formula:
LTV = ARPU × Average Customer Lifetime
For more accuracy, you can also factor in:
Do not include acquisition costs or expenses — LTV measures revenue, not profit.
Example 1: SaaS Startup
ARPU = $25 per month
Average customer lifetime = 12 months
LTV = $25 × 12 = $300
Example 2: E-commerce Store
ARPU = $50 per order
Average customer makes 3 orders
LTV = $50 × 3 = $150
Example 3: Mobile App
ARPU = $10 per month
Average customer lifetime = 18 months
LTV = $10 × 18 = $180
Your CAC must always be lower than LTV.
A high LTV compared to CAC means your startup can scale profitably and sustain growth.