What Is the Retention Rate Percentage Calculator?
This calculator measures Customer Retention Rate (CRR) — the percentage of customers a business keeps over a given period, excluding any new customers acquired during that time. It is a core metric for subscription services, SaaS, ecommerce, and any recurring-revenue business, because keeping existing customers is usually far cheaper than acquiring new ones.
How to Use It
Enter three numbers: the count of customers you had at the start of the period (S), the count at the end of the period (E), and the number of new customers you acquired during the period (N). The calculator returns your retention rate, the number of original customers retained, and the matching churn rate.
The Formula Explained
The standard retention rate formula is:
$$\text{Retention Rate} = \frac{\text{Customers at End} - \text{New Customers}}{\text{Customers at Start}} \times 100\%$$
Subtracting new customers (N) from the end count (E) isolates how many of your original customers remained. Dividing by the start count (S) and multiplying by 100 converts that into a percentage. Churn is simply 100 minus the retention percentage.
Worked Example
Suppose you started a quarter with 200 customers, ended with 210, and signed up 30 new customers along the way. Retained originals = \(210 - 30 = 180\). Retention rate = \((180 / 200) \times 100 = \mathbf{90\%}\). Churn rate = \(100 - 90 = \mathbf{10\%}\). So even though your total grew, you lost 20 of your original 200 customers.
FAQ
Why subtract new customers? Retention measures loyalty of the customers you already had. Including new sign-ups would inflate the figure and hide churn.
What is a good retention rate? It varies by industry, but SaaS companies often target 85–95% over a quarter or year. Higher is better.
How is retention different from churn? They are two sides of the same coin: retention is the share you keep, churn is the share you lose, and together they total 100%.
