Amazon BSR sales estimator
Enter a product’s Best Sellers Rank and get the monthly and daily sales that products at that rank typically make. The curve is fitted to Amazon’s own “bought in past month” figures (33,668 on Amazon US and 2,209 on Amazon AU and 663 on Amazon UK and 15,804 on Amazon DE products measured) and refit every week, with a separate fit for Australia. Free and no sign-up.
Product details
Estimated demand
Enter a BSR to see the estimate.
LumaiScope reads the measured “bought in past month” figure for a real ASIN when Amazon shows one, and only estimates when it doesn’t. Validate a product free.
How the estimate is made
- LumaiScope reads each product’s rank next to its “bought in past month” figure: every day for the products it tracks, and every week across a wider catalog of licensed Amazon history.
- Sales fall by a roughly constant factor each time rank multiplies by ten, so the curve is a straight line in those terms, fitted per marketplace and per category with enough data.
- Amazon only shows the figure from 50 sales a month, so deep in the rankings many products show none. Where the wider catalog covers a marketplace, the curve counts those products as selling under 50 and follows the typical product: half of the products at a rank sell more, half sell less.
- Amazon’s figure is a step (“1K+” means at least 1,000), so each figure is read as spread across its step. The estimate is a central value, not a minimum.
- The likely range covers about two thirds of products at a given rank.
- The curve is refit every week from recent data, so it tracks the market instead of a table someone typed in years ago.
Rank tells you volume, not profit. Once you have a demand figure, run it through the free FBA profit calculator to see what each unit actually earns, and read the guide on validating product demand for the other signals worth checking before you order.
Frequently asked questions
How does the estimator turn a BSR into sales?
Amazon shows a "bought in past month" figure on listings that sell at least 50 a month. LumaiScope reads that figure next to the product's rank, every day for the products it tracks and every week across a wider catalog of licensed Amazon history, then fits a curve for each marketplace and for each category with enough data. Where that catalog covers the marketplace, products showing no figure count as selling under 50, so the curve follows the typical product at each rank, quieter ones included. Enter a rank and the curve returns the sales that products at that rank typically make.
How accurate is it?
It is an estimate, and we show a likely range for that reason. Amazon's figure is bucketed ("1K+" means at least a thousand), rank is recalculated hourly, and two products at the same rank can sell quite differently. The range covers roughly two thirds of products at a given rank. For a specific product, the measured figure on its listing beats any estimate.
Why do the same ranks give different numbers for the US and Australia?
Rank is relative to every other product in that marketplace's category. Amazon.com.au has far fewer buyers than Amazon.com, so a rank of 5,000 in Australia sits much further down the demand curve. We fit each marketplace on its own data rather than scaling the US curve, which is why the Australian numbers are lower.
Should I use the main category rank or the sub-category rank?
The main category rank. Sub-category ranks are small pools and look flattering. The rank line on a listing reads something like "#4,512 in Kitchen & Dining" followed by sub-category ranks, and the first one is the one to enter here.
How often is the curve updated?
Weekly. Each fit uses recent readings (our own from the last 90 days, the wider catalog's from the last 30), so seasonal shifts in how rank maps to sales show up within a few weeks rather than sitting in a static table for years.
Get the measured number for a real product
Paste an ASIN and LumaiScope reads the listing’s actual sales figure when Amazon shows one, tracks its rank daily from then on, and ends in a plain-English GO / WATCH / NO-GO verdict. Start free, no credit card.
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