Churn Rate measures the percentage of customers who stop using your product or service over a specific period. It is the opposite of retention and shows how quickly your startup is losing customers.
High churn is a warning sign for startups: it can drastically reduce growth, revenue, and LTV. Keeping churn low is essential for sustainable growth and profitability.
Churn Rate = (Number of Customers Lost During Period ÷ Number of Customers at Start of Period) × 100%
Example:
Churn Rate helps answer critical questions for founders:
Reducing churn is often the fastest way to increase LTV and improve unit economics.
Simple formula:
Churn Rate (%) = (Customers Lost During Period ÷ Customers at Start of Period) × 100
Make sure to define the period (daily, weekly, monthly) and consistently track lost customers.
Do not include new customers acquired during the period; churn only measures loss of existing customers.
Example 1: SaaS Startup
Start-of-month customers = 500
Customers lost = 50
Churn Rate = 10%
Example 2: Mobile App
Start-of-week users = 1,000
Users lost = 200
Churn Rate = 20%
Example 3: E-commerce Store
Start-of-month customers = 300
Customers not returning = 90
Churn Rate = 30%
Churn is the enemy of growth — reducing churn directly increases LTV and revenue.
Focus on customer engagement, product value, and retention strategies to minimize churn.