Churn rate vs retention rate: what's the difference?

Churn rate and retention rate, defined

Churn rate is the percentage of existing customers who stop buying from you during a period. Retention rate is the percentage of existing customers who keep buying. Same period, same customers, opposite framing — which is why the two are locked together by a simple identity:

Neither metric is "more accurate" than the other; they are the same measurement wearing different clothes. What differs is what each framing makes you notice. Churn puts the loss in front of you — 300 customers gone. Retention puts the base in front of you — 1,700 still here. Teams consistently underreact to a retention number and overreact to the equivalent churn number, and that asymmetry is worth using deliberately (more on that below).

The deep calculation mechanics — inactivity windows, worked examples, cohort denominators, and what counts as "lost" — are covered in our guide to calculating customer churn rate for a Shopify store, and the revenue side of the same math lives in how to calculate customer lifetime value.

The 100% relationship: conversion table

Because the two metrics always sum to 100% on the same customer base, converting between them is arithmetic, not analysis:

The identity is simple, but compounding hides inside it. 10% monthly churn sounds survivable — yet keeping 90% of customers each month leaves you with roughly 28% of the original group after twelve months (0.90¹² ≈ 0.28). This is why a small-sounding churn number deserves more alarm than it usually gets, and why the same data framed as "90% retention" can lull a team into complacency.

When customers never cancel: the repurchase window

Subscription businesses get a clean churn signal — a cancellation. Most Shopify stores don't: a customer simply goes quiet, and you have to decide when quiet becomes gone. The standard approach is a repurchase window: a customer counts as churned once they haven't ordered within a window matched to your typical purchase cycle — 60–90 days for fast-moving consumables, up to 180–365 days for durables. Choosing that window well (and the trade-offs of each choice) is covered in the churn rate calculation guide linked above.

The practical consequence for this comparison: for a non-subscription store, both churn rate and retention rate inherit whatever window you pick. Change the window and both numbers move — so never compare this quarter's retention against last quarter's if the definition shifted in between.

Should you track churn or retention?

Both — they're free once you have either. The real question is which framing to put where:

• Use churn rate for diagnosis and alerts. Loss is what you act on. "VIP churn doubled this month" triggers a response in a way "VIP retention slipped from 96% to 92%" rarely does, even though they're the same fact.
• Use retention rate for goals and reporting. Retention frames the positive trend you're building quarter over quarter, and it's the convention most published benchmarks use — see our ecommerce retention benchmarks by industry.
• Segment either one before trusting it. A flat store-wide churn rate can hide VIPs leaving while one-time discount buyers stick around. The segment-level number is the actionable one.
• Pair them with repeat purchase rate. Churn and retention track existing customers over a period; repeat purchase rate tells you how many customers ever come back at all. Together they separate "we keep buyers once we hook them" from "we never hook them."

If you'd rather not maintain this in spreadsheets, several tools compute churn, retention, and repeat metrics continuously from your order data — our roundup of the best Shopify customer retention apps compares the options.

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