Calculate retention rate, churn rate, repeat purchase rate, and average customer lifetime
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Founder & CEO, Toolraxy
Faiq Ur Rahman is a web designer, digital product developer, and founder of Toolraxy, a growing platform of web-based calculators and utility tools. He specializes in building structured, user-friendly tools focused on health, finance, productivity, and everyday problem-solving.
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This customer retention rate calculator turns three numbers into a full picture of how well you keep the customers you already have. Enter your starting cohort size, how many new customers you added, and how many left during the period. You’ll get your retention rate, churn rate, average customer lifetime, and, if you add repeat purchase data, your repeat purchase rate. The optional revenue section estimates what your retained customers are worth and what churn is costing you.
Retention rate is the number most operators watch when they want to know if the product actually works after the first sale. This tool answers that question with the standard industry formula: the share of your starting cohort that stayed, not counting new customers.
SaaS founders use it after a pricing change. E-commerce managers use it to check whether a loyalty program is moving the needle. Agencies use it to see if monthly clients are actually renewing or just quiet. The math isn’t complicated, but a calculator removes the arithmetic and gives you the derived numbers, churn rate and average lifetime, in the same view.
I’ve seen teams track revenue retention without ever checking logo retention. That gap hides the fact that smaller accounts are leaving while a few large ones renew. This page helps you close it. Enter your numbers, read the verdict, and decide what to fix.
Select your reporting currency from the dropdown. This changes the symbol on the optional revenue fields only.
Enter the number of customers you had at the start of the period.
Add how many new customers you acquired during that same period.
Enter how many customers left or cancelled before the period ended.
Choose the period length: monthly, quarterly, annual, or weekly.
Optionally, add repeat purchasers and total purchasers to calculate repeat purchase rate.
Optionally, enter average revenue per customer and gross margin to see the revenue impact of churn.
Read the retention rate, churn rate, and average customer lifetime from the result panel.
The retention rate formula isolates your existing customers from new ones. That distinction matters because new customers inflate the ending count and make retention look better than it is.
Formula: Retention Rate = (Customers Retained ÷ Customers at Start) × 100
Where:
Customers Retained = Customers at Start − Customers Who Left
Customers at Start is your opening cohort for the period
Customers Who Left includes anyone who cancelled, didn’t renew, or was marked inactive
The calculator then derives churn rate as 100% minus retention rate. Average customer lifetime comes from dividing 100 by the monthly churn rate. If your period is quarterly, annual, or weekly, the tool normalizes everything to a monthly basis first using compound math, not simple division.
Suppose you run a mid-size B2B software company. At the start of Q3, you had 847 paying accounts. During the quarter, your sales team closed 62 new accounts. By the end of Q3, 73 of your original accounts had cancelled.
Your ending customer count is 847 + 62 − 73 = 836.
Your retained customers are 847 − 73 = 774.
Your retention rate is (774 ÷ 847) × 100 = 91.38%.
Your churn rate is 8.62% for the quarter.
The calculator converts that to a monthly basis. Monthly retention is 97.02%, monthly churn is 2.98%. Average customer lifetime works out to 33.6 months, or about 2.8 years. If your average revenue per account is $340 per month and your gross margin is 72%, the calculator estimates that you’ll collect roughly $263,000 in gross margin from the 774 retained accounts over their expected lifetime. The 73 accounts that left represent about $24,800 in lost gross margin over that same window.
Customer retention rate equals retained customers divided by starting customers, times 100. Retained customers are your starting count minus anyone who left. New customers acquired during the period are excluded from both the numerator and the denominator so the rate reflects only your existing base.
For SaaS, 90% or higher on an annual basis is a solid benchmark. Enterprise SaaS with longer contracts often exceeds 95%. Self-serve products typically land between 85% and 90%. Compare against your own historical trend and similar-sized companies rather than broad averages, since retention varies widely by price point and customer segment.
Churn rate is simply 100% minus your retention rate. If retention is 93%, churn is 7%. Retention measures the customers who stayed; churn measures the ones who left. They describe the same cohort from opposite angles. Churn is often more useful for diagnosing problems because it points directly at the customers who departed.
The calculator divides 100 by the monthly churn rate. So if monthly churn is 4%, average lifetime is 100 ÷ 4 = 25 months. This assumes a constant churn rate over time, which isn’t perfectly accurate but is the standard quick estimate used in subscription analytics.
Repeat purchase rate is the percentage of total buyers who purchased more than once during the period. It’s calculated by dividing repeat purchasers by total purchasers and multiplying by 100. A rate between 20% and 30% is generally considered good for e-commerce. The calculator computes this only if you enter both numbers in the optional repeat purchase section.
Yes. Select “Weekly” from the period dropdown. The tool normalizes weekly retention and churn to monthly equivalents using compound math. Note that weekly churn rates can be volatile, so a single week’s number may not reflect a stable trend.
When churned customers is zero, the tool can’t compute a churn rate, so average lifetime shows as infinite. This is mathematically correct but practically rare. A zero-churn period usually means inactive accounts are still marked active in your billing or CRM system. Verify your data before treating it as a real result.
Customer retention rate, sometimes called logo retention, counts customers. Revenue retention rate counts dollars. It’s possible to have high customer retention and declining revenue retention if your remaining customers are downgrading their plans. Both metrics matter, and they can tell different stories about the same customer base.
No. The industry-standard formula excludes new customers from both the numerator and the denominator. Including them inflates the retention rate and makes it harder to see whether your existing customers are actually staying. If you want to measure total growth, track customer growth rate separately.
The formula in Excel is: =((End_Customers − New_Customers) / Start_Customers) * 100. Put your ending count in one cell, new customers in another, and starting count in a third. The parentheses matter. Without them, Excel performs the division before the subtraction and gives you the wrong answer.
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