The FBA Sales Estimator reads the numbers already on a product page — price, Best Seller Rank, review count and rating — for the platform, marketplace and category you choose, and turns them into a sales estimate. Amazon or eBay, across eight marketplaces, each in its own currency.

A Best Seller Rank is a sales figure in disguise

Every product on Amazon carries a Best Seller Rank, and Amazon says it’s based on sales and updated hourly. So the demand behind any listing is sitting in plain sight on its product page — yours, a competitor’s, or one you’re thinking of stocking.

The catch is reading it. A rank is a position, not a number of units. #10,000 in a huge category can be healthy daily sales; #10,000 in a small one can be very few. And halving a rank doesn’t mean doubling the sales. That translation is the job the estimator does for you.

What the tool does

Choose where the product sells, enter its numbers, and calculate:

Key features

Category-aware, because rank is relative

Amazon ranks products against others in the same category, so a rank on its own tells you very little. Tell the estimator the category and the rank is read against that category, not taken as a raw number.

Eight marketplaces, their own currencies

From the United States to India, enter the price in the currency shoppers actually pay and read the estimate for that marketplace — useful when you’re weighing up where to launch, or whether a product that sells well at home travels.

Amazon and eBay in one place

Checking the same product on both platforms? Switch the platform, not the tool.

An estimate — and labelled as one

Amazon doesn’t publish how Best Seller Rank is calculated, and a rank moves hour to hour, so any figure built from it is an estimate. Use it to compare products and size a niche, not to promise a number. When you want Amazon’s own published figures, the Keyword Difficulty Checker adds up the “bought in past month” badges across page one of a search.

Pairs with the rest of your research

Sales are one line of the decision. The FBA Storage Calculator tells you what the stock costs to keep while it sells, the Keyword Difficulty Checker how hard the search is to win, and once it’s live, Amazon Ads AI shows the real profit after every cost.

How it works — three steps

Who it’s for

Why sellers trust it: honest estimates, not promises

Any tool that turns a rank into sales is estimating — Amazon keeps its formula to itself. This one says so. Put in real numbers from a real listing, read the result for what it is, and use it the way experienced sellers do: to compare, to rank, and to rule things out before the money is committed.

Frequently asked questions