About the Sell-Through Rate Calculator
This sell-through rate calculator measures how much of the inventory you had available actually sold during a period. Enter the units on hand at the start, units received during the period and units sold, plus the length of the period in weeks. You get the sell-through percentage, the ending inventory, the stock-to-sales ratio, the average weekly sales rate and how many weeks of supply are left at that pace.
Retail buyers, merchandise planners, e-commerce sellers and brand reps use sell-through to judge whether a product, size or season is selling as planned, when to reorder and when to mark down. Comparing sell-through across items with the same time window quickly separates winners from slow movers.
Sell-through uses units here, but the same formulas work with retail dollars if you enter values instead. The stock-to-sales ratio uses beginning-of-period stock divided by sales for the period, the standard retail planning definition. Healthy targets depend on the category and the length of the period — fashion often aims for high monthly sell-through, while basics and hard goods run lower but steadier.
With the default inputs, the sell-through rate is 65%. Change any value above to recalculate instantly.
How to use the sell-through rate calculator
- 1Enter units on hand at the start of the period.
- 2Enter units received during the period.
- 3Enter units sold during the same period.
- 4Enter the period length in weeks and your target sell-through.
- 5Review sell-through, stock-to-sales and weeks of supply to plan reorders or markdowns.
Formula and method
Sell-through compares what sold with everything that was available to sell in the period — the stock on hand at the start plus everything received. Some retailers use only units received (common for a new product launch or a single shipment); to do that, set beginning inventory to zero.
The stock-to-sales ratio divides beginning-of-period stock by sales for the period; a ratio of 2 means you started with twice what you sold. Weeks of supply divides ending inventory by the average weekly sales rate, assuming sales continue at the same pace with no new receipts. Units for target shows how many sales the target sell-through required.
- Sold
- Units sold in the period
- Beginning
- Units on hand at the start of the period
- Received
- Units received during the period
- Weeks
- Length of the period in weeks
Worked examples
Monthly sell-through for a jacket style
With 500 on hand and 300 received, 800 units were available. Selling 520 is a 65% sell-through and leaves 280 units. At 130 a week that is about 2.2 weeks of supply; the stock-to-sales ratio is 500 ÷ 520 = 0.96.
Slow-moving seasonal item
Only 180 of 1,200 units sold in six weeks — 15% sell-through. At 30 a week the remaining 1,020 units would take 34 weeks to clear, a strong signal for a markdown.
New product launch (receipts only)
Of 250 units received, 210 sold in two weeks — 84% sell-through. At 105 a week the 40 left last less than half a week, so it is time to reorder.
Frequently asked questions
How do you calculate sell-through rate?+
Divide the units sold in a period by the units available to sell (beginning inventory plus units received) and multiply by 100. If 520 of 800 available units sell, the sell-through rate is 65%.
What is a good sell-through rate?+
It depends on the category and the period. Fast fashion and seasonal goods often aim for high monthly sell-through, while basics, hardware and furniture naturally run lower. Compare items over the same window and against your own plan rather than a single universal number.
What is the difference between sell-through and inventory turnover?+
Sell-through is the share of available stock sold in a single period, expressed as a percentage. Inventory turnover is how many times average inventory is sold and replaced over a year, usually based on cost of goods sold.
What does the stock-to-sales ratio tell you?+
It compares the stock you started a period with to the sales during that period. A ratio of 3 means you held three times what you sold. Planners use it to set how much inventory to carry at the start of each month.
How can I improve sell-through?+
Buy closer to demand, test small quantities before reordering, reallocate stock between stores or channels, promote slow sizes or colors, and mark down early rather than late, when a modest discount still moves product.