E-commerce
May 6, 2026
How is ecommerce churn rate calculated? The ecommerce churn rate, or customer attrition rate, measures the share of customers who stop buying over a given period. The simplest formula is: lost customers ÷ customers at the start of the period × 100.
Example: you have 1,000 active customers at the start of the quarter. By the end, 180 have not repurchased even though they should have according to your buying cycle. Your churn is 18%. This measure seems simple, but it requires a clear definition of what a lost customer is.
In ecommerce, churn is more delicate than in a subscription business. A customer who does not buy for 30 days is not necessarily lost if your product is repurchased every 6 months. Shopify notes that churn is linked to retention and customer lifetime value, with a basic formula centered on lost customers compared with customers at the start (Shopify).
In this guide, you will see how to calculate ecommerce churn, which period to choose, how to avoid mistakes, and how to connect this KPI to LTV, average order value, and loyalty. To go further, read why your churn is too high and customer retention and LTV.
Summary
Definition of e-commerce churn rate
E-commerce churn rate measures the share of customers who stop buying from a brand over a given period. In French, it is also called attrition rate. The higher this rate, the faster the brand loses its existing customers.
A loyalty indicator
Churn is not just a financial metric. It shows whether your customers come back, whether your experience delivers on its promises, and whether your brand is building a lasting relationship.
Why it is more ambiguous in e-commerce
In a subscription, churn is visible: the customer cancels. In a traditional store, the customer does not always say they are leaving. They simply stop buying. You therefore need to define a consistent period of inactivity.
Concrete example
If you sell coffee, a customer who has not bought for 90 days may be considered at risk. If you sell a mattress, 90 days without a purchase means nothing. The product cycle completely changes how churn is interpreted.
The right question
Churn requires answering a simple question: after how long without an order is a customer probably lost to my brand?
The main churn formula
The most common formula is: churn rate = customers lost during the period ÷ customers at the beginning of the period × 100.
Simple example
At the beginning of the month, you have 2,000 active customers. During the month, 120 customers become inactive according to your definition. The calculation is: 120 ÷ 2,000 × 100 = 6%. Your monthly churn is therefore 6%.
Why start with the customers at the beginning
We start with the customers at the beginning to prevent new customers acquired during the period from masking the loss of existing ones. Otherwise, strong acquisition can make it seem like everything is going well when the existing base is actually shrinking.
Retention-based formula
You can also calculate churn using retention: churn = 100% - retention rate. If your retention is 72%, your churn is 28%.
Watch the unit
Do not mix customers, orders, and revenue. Customer churn measures customers. Revenue churn measures lost revenue. Both are useful, but they do not mean the same thing.
Define a lost customer in a non-subscription store
This is the most important part. In a standard e-commerce business, a lost customer is not always obvious. You need to build a business rule.
Start from the repurchase cycle
Look at the average time between two orders. If your customers reorder on average every 45 days, 120 days of inactivity can be a churn signal. If the average time is 9 months, that threshold would be too short.
Use a grace period
Add a buffer to avoid classifying customers as lost too quickly. A customer may be on vacation, waiting for a promotion, or have enough stock at home.
Segment by product
A consumable product, an accessory, a fashion item, and durable equipment do not have the same purchasing rhythm. Churn sometimes needs to be calculated by category.
Segment by customer
A new customer who has bought only once is different from a loyal customer with ten orders. Losing the latter is often more worrying.
Distinguish inactive from lost
An inactive customer is not always lost. They may simply be between needs. Create two statuses: at risk, then churned. This makes it possible to launch reactivation actions before considering the relationship lost.
Document the rule
Write down your definition. Example: a customer is considered churned if they have not ordered in 120 days, while their segment normally reorders in less than 60 days.
Calculate churn with a complete example
Let’s take a cosmetics store with an expected repurchase cycle of 60 to 90 days.
Step 1: define the period
The brand chooses to measure quarterly churn. This is consistent with its product cycle. Measuring every week would create too much noise.
Step 2: count the customers at the start
On January 1, it has 8,000 active customers. An active customer is a customer who has ordered at least once in the last 180 days.
Step 3: count the lost customers
On March 31, 960 customers from the initial group had not repurchased and had passed the defined inactivity threshold. They are considered churned.
Step 4: apply the formula
960 ÷ 8,000 × 100 = 12%. Quarterly churn is therefore 12%.
Step 5: interpret
This number alone is not enough. You need to look at possible reasons: lower quality, delays, price, competition, lack of follow-up, post-purchase experience, or customer service.
Step 6: track the trend
An isolated month can be misleading. Track the trend over several periods and note major changes: new range, new campaign, price increase, or delivery changes.
Customer churn, revenue churn, and product churn
Customer churn is the best known, but there are several useful ways to look at it.
Customer churn
It measures the number of lost customers. It is the best metric for tracking the loyalty of the customer base.
Revenue churn
It measures lost revenue due to customers who no longer buy again. A small number of large lost customers can have more impact than a long list of small customers.
Product churn
It looks at products or categories that do not trigger repeat purchases. A product may convert very well on the first order but retain customers poorly.
Why compare the three
If customer churn rises but revenue churn remains stable, you may mostly be losing small customers. If revenue churn increases, the problem is more serious for margin.
Link with average order value
A high average order value does not always offset high churn. To manage revenue, connect churn, purchase frequency and AOV : calculate and increase AOV.
Which time period should you choose to calculate churn?
The choice of period strongly changes the result. Monthly, quarterly, and annual churn do not tell the same story.
Monthly
Useful for subscriptions, frequent consumables, boxes, food, beauty, or products with quick repeat purchases. But it can be too volatile for durable products.
Quarterly
Often practical for e-commerce. It leaves enough time for customers to buy again, while allowing you to react quickly.
Annual
Useful for products with long cycles, seasonal brands, or highly considered purchases. It provides a more stable view.
Cohorts
The best view often consists in following cohorts of customers acquired in the same month. You see how many come back after 30, 60, 90, 180, or 365 days.
Example of cohort analysis
If the January cohort retains 35% of customers after 90 days, but the March one only 22%, look for what changed: acquisition, featured product, discount, delivery time, or support quality. The cohort makes the problem more visible than an overall average.
Do not change without reason
Keep a stable method. If you change the period or the definition, note it in the reporting. Otherwise, you may think churn is changing when only the method has changed.
Why churn is important for LTV
Churn is one of the drivers of LTV. The longer a customer stays, the more they can order, recommend the brand, and make the acquisition cost profitable.
Simple link with customer lifetime
A simplified formula estimates lifetime with: 1 ÷ churn. If monthly churn is 5%, the theoretical lifetime is about 20 months. It's only an approximation, but it helps understand the impact.
Example with LTV
If a customer orders 3 times a year, with an average basket of €60, they generate €180 per year before margin. If they stay 2 years, the gross value is €360. If they stay 3 years, it rises to €540. Reducing churn therefore increases value without necessarily increasing traffic.
Impact on CAC
If you lose customers too quickly, you have to keep buying new customers. CAC becomes heavier. The guide CAC vs LTV explains this link.
Impact on margin
A loyal customer often costs less to win back than a new customer to acquire. They know the brand, the product, and the promise. Loyalty therefore protects margin.
Impact on growth
A store can grow through acquisition while losing its historical customer base. Churn makes it possible to see whether growth rests on a healthy base.
Common causes of high churn
High churn is not always caused by price. It can come from the entire experience.
Poor first experience
Slow delivery, damaged product, disappointing packaging, incorrect size, slow support: a bad first order greatly reduces the chances of repeat purchase.
Marketing promise too strong
If advertising promises more than the product delivers, the customer buys once and does not come back. The conversion rate may be good, but churn reveals the problem.
Lack of follow-up
Some customers want to buy again but forget. Replenishment emails, recommendations, and reminders can reduce churn. Read: e-commerce email flows.
Too few complementary products
If the range gives no reason to return, churn can remain high even with good satisfaction.
Price or perceived value
The price becomes a problem when the customer no longer sees the value. Before lowering prices, check the education, the proof, the expected results, reviews, and the comparison with alternatives.
Insufficient customer service
A question without an answer, a poorly handled return, or an ignored complaint can break the relationship. To go further: e-commerce customer experience.
How to reduce e-commerce churn
Reducing churn means giving customers good reasons to come back, without hounding them.
1. Improve the first order
The first experience influences everything. Check delivery, quality, packaging, instructions, follow-up and support. A reassured customer is easier to retain.
2. Create repurchase moments
If your product is consumable, send a reminder at the right time. If your product is used with accessories, recommend them after purchase.
3. Segment follow-ups
A VIP customer, a new customer, an inactive customer and an unhappy customer should not receive the same message.
4. Build a loyalty offer
Points, benefits, early access, gifts, useful content or enhanced service can support customer return. Useful guide: effective loyalty programs.
5. Listen to weak signals
Reviews, support tickets, feedback, product questions and a drop in email open rates often indicate churn before it is visible in sales.
6. Measure after each action
A reactivation campaign can bring customers back, but it can also attract mostly discount hunters. Measure the second order after reactivation, not just the immediate sales spike.
Common mistakes in calculating churn
Churn can quickly become misleading if the method is unclear.
1. Counting new customers in the starting base
Churn should measure the loss of an existing base. If you mix new and existing customers, acquisition can mask attrition.
2. Choosing too short a period
A customer inactive for 30 days is not lost if your product is repurchased every 6 months. The period must match the purchase cycle.
3. Ignoring seasonality
Some brands sell mainly at Christmas, in summer, or during specific events. Churn calculated out of season may seem too high.
4. Mixing churn and product returns
A product return is not necessarily churn. A customer may return one size and buy another. Track the return rate separately.
5. Confusing silence and dissatisfaction
A customer who does not respond to emails is not necessarily dissatisfied. They may simply not need the product. Cross signals before concluding: purchases, visits, tickets, reviews, returns, and email engagement.
6. Not segmenting
A global churn rate can hide a specific problem: a campaign, a product, a cohort, or a country. Segmentation makes the metric actionable.
Qstomy: Spotting churn signals before they become costly
Churn doesn't always happen all at once. It often starts with hesitation, an unanswered question, a poor understanding of the product, or frustration after purchase.
Qstomy, AI assistant for Shopify, helps customers get clear answers before and after purchase. It can support customer support, recommend the right product, explain the difference between two models, or guide a customer toward a suitable solution.
The questions collected in analytics also provide useful signals. If many customers ask the same question about a size, a refill, compatibility, or delivery time, you can improve the product page, the post-purchase email, or the repurchase journey.
The goal is not just to sell more on the first visit. It's to build a clearer experience that makes people want to come back. To discover the approach, request a demo, check out the plans, or explore the AI sales assistant angle.
Summary, FAQ, and Further Reading
In brief
Definition : e-commerce churn measures customers who stop buying.
Formula : lost customers ÷ customers at the start of the period × 100.
Key : clearly define when a customer is considered lost.
Analysis : segment by cohort, product, channel, customer, and period.
Action : improve first experience, follow-ups, loyalty, and support.
FAQ
What is the e-commerce churn formula?
The basic formula is: customers lost during the period divided by customers at the start of the period, then multiplied by 100.
How do you know when a customer is lost?
Define an inactivity period according to your repurchase cycle. A coffee customer is not treated the same as a furniture customer.
What's the difference between churn and retention?
Retention measures retained customers. Churn measures lost customers. Simply put, churn = 100 % - retention.
Is churn useful without a subscription?
Yes, but it requires a business rule. It helps identify customers who no longer come back, even without a formal cancellation.
How can you reduce churn quickly?
Start with the cohorts with the most lost value. Analyze first order, returns, support, follow-ups, and repurchase offers.
To go further
Enzo
May 6, 2026
