What is inventory sell-through?
Sell-through rate is the percentage of available units sold during a defined period. It helps you compare sales with the inventory you had available, instead of judging demand by units sold alone.
Important: Sell-through has more than one common definition. Some teams measure sales against units received; others use units available during the period. Use a consistent definition when comparing products or reports.
The sell-through formula
Sell-through rate (%) = units sold ÷ (units sold + ending inventory) × 100
This is a practical unit-based method for a simple period when sold units plus ending stock reasonably represents the available units. Returns, transfers, adjustments, and replenishment during the period can make that approximation less reliable. When accurate beginning-stock and receipt data are available, calculate units available using those records instead.
Worked example: calculating sell-through
Suppose a Shopify merchant sold 45 units of a cotton tote over 30 days and has 55 units remaining. Using the simplified formula:
45 ÷ (45 + 55) × 100 = 45% sell-through
The merchant sold 45% of the 100-unit total represented by sales and remaining stock. This does not mean the item is automatically performing well or poorly: that depends on its selling period, category, seasonality, margins, and purchasing goals.
Compare variants, not just products
Different colors and sizes may behave very differently. The example below shows why a product-level average can hide slow-moving variants.
| Illustrative variant | Units sold | Ending stock | Sell-through |
|---|---|---|---|
| Cotton Tote / Natural | 45 | 55 | 45% |
| Cotton Tote / Black | 8 | 72 | 10% |
| Cotton Tote / Olive | 30 | 20 | 60% |
Illustrative figures only. These are not actual Shopify store data or InventoryPulse results. Each row uses the simplified formula above.
Natural and Olive have higher sell-through than Black in this example. That is a reason to investigate purchasing and merchandising by variant, not a universal instruction to increase or stop buying stock.
How to calculate sell-through for Shopify products
- Choose a time window. For example, the last 30, 60, or 90 days. Compare similar seasons and product ages.
- Find units sold. Use Shopify sales or order reports for the product or variant, accounting consistently for returns and cancellations.
- Find inventory quantities. Record ending stock and, when possible, starting stock, receipts, and adjustments for the same window.
- Apply one formula consistently. Be explicit about whether your denominator is units received, total available stock, or the simpler sold-plus-ending-stock approximation.
- Review the exceptions. Consider stockouts, newly launched items, seasonality, and replenishments before comparing performance.
Sell-through versus sales velocity
Sell-through is a percentage of available stock sold. Sales velocity is the number of units sold per unit of time, such as units per day. A product may sell steadily while still having low sell-through if inventory is unusually large. Looking at both measures gives a more useful picture.
What is a good sell-through rate?
There is no single ideal percentage for every Shopify merchant. Targets depend on product type, category, product lifecycle, seasonality, and inventory strategy. Compare like-for-like items and choose targets that reflect your business rather than treating one benchmark as a rule.
How InventoryPulse helps
InventoryPulse brings product- and variant-level sell-through, sales velocity, stock information, and inventory recommendations together. Merchants can also configure sell-through targets by product type and use Ask InventoryPulse to explore inventory questions. The insights support purchasing decisions; they do not guarantee future demand.
Explore InventoryPulse on Shopify
Frequently asked questions
Can sell-through exceed 100%?
Not under the simplified units-sold divided by sold-plus-ending-inventory formula when quantities are nonnegative. Other reporting definitions and inventory adjustments can produce different outcomes, so always check the method used.
Should I use revenue or unit quantities?
The calculation on this page uses units. Revenue-based measures answer different questions and should be labeled separately.
How is low sell-through different from dead stock?
Low sell-through means only a small proportion of available stock sold during the period. Dead stock generally refers to inventory with little or no expected demand. Read our guide to identifying dead stock in Shopify for a practical screening process.