Work out the share of customers you kept over a period from the start count, end count and new customers added.
Enter customers at the start and end, and how many were new.
Runs in your browser; nothing you enter leaves this page.
New customers are taken out of the end count so only the ones you already had remain. Start with 500, end with 520 after adding 70 new: 450 were kept, which is 90%.
retention = (end − new) ÷ start × 100
Churn is the other side, 100% minus retention. The tool also gives customers kept and lost, and overall customer growth, which counts the new ones.
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