# Sell-through

Sell-through is the share of available stock that sold in a period: units sold divided by units available, usually tracked weekly or over a season.

Also called: sell through

- **Measures:** The share of available stock that sold in a period.
- **Formula:** Units sold ÷ (opening stock + units received) × 100.
- **Watch for:** Reading it without the time elapsed. 40% is strong in week 2 and weak in week 10.

## What it means for retail and category teams

Available stock is typically opening stock plus receipts in the period. Sell-through is read against time: 40% after two weeks of a twelve-week season is strong, and 40% after ten weeks is a problem. Fashion and seasonal teams track it by style, colour and size, because a line can sell well overall while some sizes run out and others sit.

Sell-through is a retailer's measure of how much stock reached shoppers. Sell-in is a supplier's measure of how much stock it sold into a retailer. A supplier can report strong sell-in while sell-through is weak and unsold units are building up in stores.

## Why it matters

Sell-through is one of the earliest reliable signals that a buy was right or wrong, well before the season's margin is known. It helps teams back winners, time markdowns on slow lines, and improve availability between stores. It also answers a different question from units sold: 40 units sold out of 50 and 40 out of 400 are very different results.

## Illustrative example

The business and figures are illustrative. None of it is customer data.

A retailer receives 400 units of a knit style at the start of a 12-week autumn season. After three weeks, 120 have sold: 30% sell-through against a 25% plan. By size, small has sold 40 of 100 and medium 48 of 120, both 40%. Large has sold 26 of 100, and extra large 6 of 80. The team reorders small and medium while there is time to land them, and moves extra-large stock to the stores where it sells.

**Knit style after 3 of 12 weeks: 120 of 400 sold**

| | Units sold of units received | Result |
| --- | --- | --- |
| Small (40 of 100) | 40 of 100 | Ahead of plan |
| Medium (48 of 120) | 48 of 120 | Ahead of plan |
| Large (26 of 100) | 26 of 100 | On plan |
| Extra large (6 of 80) | 6 of 80 | Behind plan |

Reference line: Plan at week 3: 25%.

The style is ahead of plan at 30%, but extra large is far behind.

## Calculate sell-through

Sell-through = units sold ÷ (opening stock + receipts) × 100

Available units here means opening stock plus receipts. Compare the result with the time elapsed in the season.

[Use the calculator](https://twelfth.ai/tools/sell-through), [explore the worked examples](https://twelfth.ai/tools), [download the Excel / Google Sheets workbook](https://twelfth.ai/resources/retail-metrics-template.xlsx) or [download this metric's CSV template](https://twelfth.ai/resources/retail-csv/sell-through.csv).

## Common questions

### How do you calculate sell-through rate?

Divide units sold in the period by units available, which is opening stock plus units received, and multiply by 100. A style that received 400 units and sold 120 has a 30% sell-through.

### What is the difference between sell-through and sell-in?

Sell-through is how much of a retailer's stock reached shoppers. Sell-in is how much stock a supplier sold to the retailer. Strong sell-in with weak sell-through means unsold units are building up in stores, which usually leads to markdowns or returns.

### What is a good sell-through rate?

It depends on how far into the season you are and what the plan expected by now. 40% after two weeks of a twelve-week season is strong; 40% after ten weeks is a problem. Compare actual sell-through with the plan for the same week, by size and store as well as in total.

### Should sell-through be measured in units or dollars?

Usually units, because it measures how much of the stock has moved. Sell-through in dollars at retail value mixes in price changes and markdowns, so a line can look better or worse than its unit movement.

## Related concepts

- [Weeks of cover](https://twelfth.ai/glossary/weeks-of-cover): Check how long the remaining stock could last at the current sales pace.
- [Markdown](https://twelfth.ai/glossary/markdown): Test the margin effect if a slow seasonal line needs a lower price.
- [GMROI](https://twelfth.ai/glossary/gmroi)
- [Stockout](https://twelfth.ai/glossary/stockout)

## Next step

### Work through an availability decision

Bring a product that keeps running short or sitting too long. We can examine the stock, demand and options together.

- [Book a demo](https://twelfth.ai/book-a-demo)
- [twelfth for fashion & apparel](https://twelfth.ai/industries/fashion-apparel): Sell-through by size and option, markdown candidates ranked by the cost of waiting, and a record the next range review can use.

Source: https://twelfth.ai/glossary/sell-through