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Churn Calculator
Use this free churn calculator to find out how fast your business is losing customers. Enter how many customers you started with, how many left, and the length of the period, and you will get your customer churn rate, the number of customers retained, and the average customer lifetime — plus your revenue churn rate and a lifetime value hint if you add revenue figures.
Revenue fields are optional. Leave them blank if you only want the customer churn rate.
| Figure | Amount |
|---|---|
| Customer churn rate (period) | 4.00% |
| Monthly churn rate | 4.00% |
| Customers retained | 960 |
| Retention rate | 96.00% |
| Average customer lifetime | 25.0 months |
| Revenue churn rate | — |
| Estimated lifetime value per customer | $1,250.00 |
Retention over 12 months
The curve assumes the same monthly churn rate each month, with no new customers added.
How it works
Churn is the share of your customers who stop buying from you during a period. A gym loses members who cancel. A software company loses subscribers who do not renew. Whatever the business, the idea is the same: some customers stay, some leave, and the churn rate tells you what fraction left. A low rate means customers are happy enough to stay.
The calculator needs two numbers to work. The first is customers at the start of the period: how many paying customers you had on day one. Count each customer once, even if they buy more than one product, and do not count free trial users who never paid. The second is customers lost in the period: how many of those starting customers cancelled, did not renew, or stopped paying before the period ended.
The third input is the period length: monthly, quarterly, or annual. This matters because a 4 percent monthly churn rate and a 4 percent annual churn rate are very different things. A monthly rate of 4 percent means about 39 percent of customers are gone after a year if nothing changes, while an annual rate of 4 percent means 96 percent are still there.
Retention rate = 100% − churn rate
Monthly churn = 1 − (1 − period churn)1 ÷ months in period
Average customer lifetime (months) = 100 ÷ monthly churn %
Revenue churn rate = revenue lost ÷ revenue at start × 100
The revenue fields are optional, but they add a useful second view. Monthly recurring revenue at start is the total subscription revenue those starting customers were paying each month. Revenue lost is the monthly revenue that disappeared when customers cancelled. Divide the second by the first and you get revenue churn. Revenue churn can be lower than customer churn when the customers who leave are your smallest accounts, or higher when a few large accounts cancel.
The average customer lifetime comes straight from the monthly churn rate: divide 100 by the monthly churn percentage. At 4 percent monthly churn, the average customer stays 25 months. At 2 percent, the average lifetime doubles to 50 months. That is why small improvements in churn are worth so much — cutting churn from 4 percent to 3 percent lifts average lifetime from 25 months to about 33 months.
The lifetime value hint multiplies the average revenue per customer per month by the average lifetime in months. It is a rough guide to what one typical customer is worth in revenue over their whole stay, before costs. Compare it with what it costs to acquire a customer: if lifetime value is several times the acquisition cost, the business can afford to invest in growth.
The chart under the results shows the retention curve: how many of your starting customers would still be with you after each of the next 12 months if the monthly churn rate stayed the same and no new customers joined. It is a simple projection, not a forecast, but it makes the cost of churn visible in a way a single percentage never does.
Worked example
A small software business starts the month with 1,000 customers. During the month, 40 customers cancel their subscriptions. Each customer pays $50 a month on average. The business wants to know its monthly churn rate, how many customers it kept, and how long the average customer stays.
Step 1: Customer churn rate — 40 ÷ 1,000 × 100 = 4.00%. The period is one month, so the monthly churn rate is also 4.00%.
Step 2: Customers retained — 1,000 − 40 = 960 customers stayed. The retention rate is 100% − 4.00% = 96.00%.
Step 3: Average customer lifetime — 100 ÷ 4.00 = 25.0 months. The typical customer stays for just over two years.
Step 4: Estimated lifetime value — $50 × 25.0 months = $1,250.00 of revenue per customer over their whole stay.
The tool gives a customer churn rate of 4.00% per month, 960 customers retained, a retention rate of 96.00%, an average customer lifetime of 25.0 months, and an estimated lifetime value of $1,250.00 per customer. If the business cut churn to 3 percent, lifetime would rise to about 33.3 months and lifetime value to about $1,666.67 — an extra $416.67 per customer without winning a single new one.
FAQ
What is a good churn rate?
It depends on the business, but for most subscription businesses a monthly churn rate of 2 to 5 percent is typical, and under 2 percent is strong. Business-to-business software often aims for under 1 percent a month, while consumer apps and gyms commonly see 5 percent or more.
How do you calculate churn rate?
Divide the number of customers lost during a period by the number of customers you had at the start of that period, then multiply by 100. If you started a month with 1,000 customers and lost 40, the churn rate is 40 divided by 1,000, times 100, which is 4 percent. Use the same period for both numbers, and count only customers who actually left, not customers who paused or downgraded.
What is the difference between customer churn and revenue churn?
Customer churn counts people: the share of customers who leave in a period. Revenue churn counts money: the share of monthly recurring revenue lost in the same period. The two can differ a lot. If your biggest customers stay and only small accounts leave, revenue churn will be lower than customer churn. If a few large accounts cancel, revenue churn can be higher even when only a handful of customers leave.
How do I reduce churn?
Start by finding out why customers leave: read cancellation reasons, survey recent leavers, and look for patterns in who leaves and when. Then fix the most common cause first — often a confusing first week, a missing feature, a price that no longer fits, or support that is slow to answer.
What is the difference between churn rate and retention rate?
They are two sides of the same number. Retention rate is the share of customers who stay, and churn rate is the share who leave, so the two always add up to 100 percent. If 4 percent of customers churn in a month, 96 percent are retained.