How to Calculate Reorder Rate (Formula + Example)

What is reorder rate?

Reorder rate is the percentage of customers who purchase a replenishable product again after their first order of it. Where repeat purchase rate counts any second order, reorder rate is deliberately narrower: it tracks whether customers come back for the same consumable they already bought. That focus makes it one of the most honest measures of product-market fit for consumable brands.

A strong reorder rate means customers are consuming the product, valuing it, and returning to restock — the core loop a consumable business depends on. A weak reorder rate, even alongside healthy acquisition, signals that the post-purchase moment is being missed or that the next prompt arrives at the wrong time.

The reorder rate formula

Reorder Rate = (Customers who reordered ÷ Customers who bought the product) × 100

• Customers who reordered — distinct customers who placed a second (or later) order containing the same product or an eligible replenishable item, within the measurement window.
• Customers who bought the product — distinct customers who bought that product at least once during the same window.
• × 100 — converts the ratio to a percentage.

You can calculate reorder rate per SKU, per category, or across all replenishable products. Per-SKU rates are the most diagnostic, because they reveal which products drive the replenishment loop and which don't.

How to calculate reorder rate: a worked example

Consider a single flagship SKU — a 30-day supply product — measured over a 90-day window.

1. Count first-time buyers of the SKU. In the period, 2,000 distinct customers bought the product.
2. Count reorders. Of those, 700 came back and bought the same product again within the window.
3. Divide. 700 ÷ 2,000 = 0.35.
4. Convert to a percentage. 0.35 × 100 = 35%.

The SKU has a 35% reorder rate over 90 days. Because the product lasts roughly 30 days, a 90-day window gives customers time for at least two natural refill opportunities. If the brand shortened the window to 30 days, the rate would look artificially low simply because many customers wouldn't have run out yet.

What's a good reorder rate?

Reorder rate benchmarks are highly category-dependent, so use external numbers loosely. For consumable ecommerce brands, reorder rates often land in the 25–45% range within a product's consumption cycle, with replenishment-focused brands pushing higher. Faster-consumed staples tend to reorder at higher rates than occasional or seasonal items.

The most useful comparison is against your own SKUs and cohorts. Rank products by reorder rate to find your true replenishment drivers, then watch whether newer cohorts reorder faster than older ones. A rising per-cohort reorder rate is strong evidence that your post-purchase timing is improving.

How to improve reorder rate

Reorder rate is mostly a timing problem. A customer who has run out is ready to buy; a customer who hasn't isn't. The brands that win at reorder rate stop blasting the same reminder on a fixed schedule and instead match the prompt to each customer's actual consumption pace, so the nudge lands right as the product runs low and the path back to checkout is short.

An AI replenishment engine like reOtter is built around exactly this loop: it predicts per-customer, per-SKU run-out, fires a reorder reminder at the right moment, and sends the customer to a one-click reorder storefront so restocking takes a single tap. By aligning the prompt with genuine need rather than a calendar, that approach lifts reorder rate without relying on steeper discounts. The merchant owns the timing rules; the AI handles the per-customer math.

Key takeaways

• Reorder rate = customers who reordered ÷ customers who bought the product × 100, per SKU or category.
• Size your window to at least one full consumption cycle plus buffer, or the rate will read artificially low.
• The biggest lever is timing the reminder to predicted run-out and making the reorder path one click.

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