MRR, ARR, GRR, and NRR: Subscription Metrics for Ecommerce

A store that sells a refill subscription has a different revenue pattern from a store whose customers occasionally return. Both can be good businesses, but only the first has a defined recurring arrangement. Use subscription metrics for that recurring portion and keep ordinary one-time sales separate.

MRR and ARR describe normalized recurring revenue. They are not bank balances, guaranteed future collections, or substitutes for accounting revenue recognition.

Calculate MRR and ARR

Monthly recurring revenue, or MRR, normalizes active recurring charges to a monthly basis under a documented policy. A hypothetical store with 100 active subscriptions at $30 per month has $3,000 MRR before adjustments for discounts, pauses, failed payments, or other policy choices.

Annual recurring revenue, or ARR, is commonly MRR multiplied by 12. That example produces $36,000 ARR. Stripe documents this relationship. Multiplying one unusually strong retail sales month by 12 does not turn the result into recurring revenue. [Source: Stripe MRR and ARR.]

Annual subscriptions require normalization: an eligible $240 annual recurring subscription corresponds to $20 monthly recurring revenue under a simple model. The cash might arrive at once, while the normalized metric spreads it over the year.

Use a starting cohort for retention

Gross revenue retention, or GRR, measures how much of the starting recurring revenue remains after churn and contraction, without adding expansion or new customers. The formula is:

GRR = (starting recurring revenue − churned revenue − contraction) / starting recurring revenue × 100

Suppose you start with $10,000 MRR, lose $1,000 to cancellations, and lose $500 when customers reduce their plans. GRR is 85%. In this formulation it cannot exceed 100%. Stripe's explanation uses the same starting-revenue logic. [Source: Stripe GRR.]

Net revenue retention, or NRR, includes expansion within that same starting customer group:

NRR = (starting revenue − churn − contraction + expansion) / starting revenue × 100

If those existing customers add $2,000 in upgrades or additional subscriptions, NRR is 105%. New customers acquired during the period remain excluded from both retention calculations. Define how you handle reactivations and apply that policy consistently.

Distinguish customer and revenue churn

Customer churn counts customers who leave; revenue churn measures the recurring revenue lost. Losing five small subscriptions and losing five large subscriptions can produce the same customer churn but very different revenue impact.

Separate voluntary cancellations from payment-related losses where you can. Ask why people cancel without making cancellation unnecessarily difficult. A payment reminder solves a different problem from a product that arrives too often.

Do not let expansion hide dissatisfaction

An NRR above 100% can coexist with meaningful cancellations. Review GRR, customer retention, product experience, failed payments, contribution, and support issues together. More revenue from a few expanding customers does not mean everyone is satisfied.

Track delivery success and subscription changes by cohort. For a replenishment business, excessive inventory in the customer's home may signal that the default frequency is wrong. Offering a suitable skip or schedule option can improve fit, though its effect should be measured rather than assumed.

If your store has no recurring contracts, begin with repeat purchase rate, purchase frequency, time to second order, and observed customer contribution. Choose metrics that describe the actual business model rather than making ordinary retail revenue sound more predictable than it is.