How to calculate repeat purchase rate for a cohort of new customers
The short answer
Repeat purchase rate is the share of customers who buy again within a set window. Take everyone who made a first purchase in a defined period, count how many bought a second time within six months, then divide by the cohort size. Compare cohorts by channel and first product to see where repeat buyers come from.
Second purchase rate, cohort by channel
Why it matters
The second purchase is the first sign a new customer will stay, and every later purchase depends on it. A cohort view shows whether your acquisition brings in customers who return, and which channels, first products and offers produce them.
The question to ask
Copy this into Lexi as written.
How to work it out
1. Define the cohort. Include every customer whose first order falls in your chosen period, such as the first half of last year, with one record per person across channels.
2. Count second purchases within the window. Count the cohort members who placed another order within six months of their first, in store or online.
3. Divide and compare. Divide repeat buyers by cohort size, then compare by acquisition channel, first product and discount used on the first order.
What the answer looks like
Illustrative output on sample data
Illustrative example: how Lexi answers this for a sporting goods retailer. It builds a cohort of every customer whose first order fell between January 1 and June 30 last year, with store and online orders matched to one person.
- Cohort: 18,400 new customers, 4,600 bought again within six months. Repeat purchase rate = 25%.
- First bought in store: 32% repeat.
- First bought online at full price: 25% repeat.
- First bought online with a 25% welcome discount: 15.2% repeat.
What the data shows
The discount cohort repeats at under half the rate of store-acquired customers.
What it means
The welcome offer wins first orders without winning second ones. Store customers who first bought online would have gone uncounted without matched records.
What to do
Test a smaller welcome offer, and add a second-purchase prompt at around 60 days for discount-acquired customers.
Would you like the same cohort split by first product category?
Frequently asked questions
What is a good repeat purchase rate?
Your own cohorts make the most reliable yardstick, because repeat rates swing with the purchase cycle: shoppers restock consumables within weeks but replace a sofa every few years. Calculate the six-month rate for each quarterly cohort over two years, then judge every new cohort against that range. A falling trend matters more than any single figure.
Why use a cohort instead of all customers?
A cohort fixes the starting point, so every customer has the same time to return. Rates across all customers mix new and long-standing buyers, which hides whether recent acquisition is improving or slipping. Cohorts by acquisition month or quarter show the trend clearly and make channels comparable.
Do store purchases count as repeat purchases?
Yes, once you match them to the same customer. If online and store orders sit under separate records, the repeat rate looks lower than it is, because a customer who bought online and returned to a store counts as two one-time buyers. Resolve identity across channels first.