What is sell-through rate? How Strooply measures demand.

Sell-through rate compares how many of an item sold in a period with how many were available to buy. A high rate means most of the supply found a buyer. A low rate means a lot of listings are sitting. eBay's Product research lists a sell through rate among its results, for searches of items sold 90 days ago or less.¹

For a reseller it is a quick read on demand. A good sold price on an item nobody buys is a trap, because the item can sit in your stock for months. Sell-through rate is the check that catches it.

Strooply uses this formula, shown as a percent:

Sell-through rate = items sold in the period, divided by (items sold plus items currently listed).

The period is the last 90 days of sales. The listed count is today's active eBay listings for the same item. Because the sold items are part of the total, the result can never go above 100%.

Strooply also filters the results to the same item before counting. Lots, bundles and parts-only listings are removed, so a box of ten phones does not count as one sale of your phone.

These are sample numbers, not real data for any item. Say 12 copies of an item sold in the last 90 days and 18 are listed right now.

• Sold plus listed: 12 + 18 = 30.
• Sell-through rate: 12 divided by 30 = 40%.
• Demand rating: 40% falls in the Healthy band, described below.
• Sales per day: 12 sales over 90 days is about 0.13 a day.
• Days to sell: 18 listed divided by 0.13 a day is about 135 days to work through today's supply.

You can try your own numbers in the sell-through rate calculator, which also explains the maths in more detail.

Many resellers work it out as sold divided by active instead. With the sample numbers that is 12 divided by 18, or about 67%. Neither version is wrong, they answer slightly different questions. Sold divided by active is a ratio of sales to what is on offer and can go above 100%. The version Strooply uses is capped at 100% and reads as the share of all supply, sold and listed, that sold.

When you compare figures from different tools, check which formula each one uses and what time window it covers. Two honest tools can show different rates for the same item.

In Strooply's research results, the sell-through rate sets a Demand rating:

• High: 60% or more.
• Healthy: 25% up to 60%.
• Low: under 25%.
• Stagnant: no sales at all in the window.

These bands are Strooply's own rules of thumb, not an eBay standard. A rating describes past sales and current listings. It does not predict what your own listing will do.

Under the Demand rating, Strooply can show an estimate such as "~45d to sell". It is the number of active listings divided by the average sales per day, measured over the sales history window. It is a rough guide to how long today's supply would take to clear at the recent pace. When the estimate is over a year, it shows "1 yr+".

It is not a forecast for your listing. Your price, photos, title and timing all change how long yours takes.

Strooply's sales history covers up to 6 months of recent eBay sales per search, where available. It comes from third-party data providers. For some items the history is shorter, so a rate based on a thin history deserves less trust.

Best Offer sales show the listed price, because the accepted amount is not public. The real sale price may be lower, so figures such as the median sold price are estimates. The seller always sets the price.

Small samples mislead. A rate built from three sales swings wildly with one more or one fewer. Seasonal items also move: a winter coat looks stagnant in July. For the bigger picture on reading sold figures, see the guide to sold prices.

Demand is only half of a buying decision. Work out what you would keep after eBay fees, shipping and your cost in the eBay fee and profit calculator, and set a ceiling with the max buy price calculator. Packing costs belong in the plan too, and the shipping supplies guide helps with those.

When you research an item, the results show four tiles: Active, Sold, Demand and Median sold. Active is the count of current eBay listings and Sold is the count of recent sales. Demand is the rating described above, with the days to sell estimate beneath it, and Median sold is the middle sold price. The Sold and Active tabs list the individual listings behind the numbers, so you can check that they match your item. See how Strooply works.