BSR (Best Sellers Rank), sometimes called "Sales Rank," is a number Amazon assigns to every product with at least one sale. BSR #1 in a category means that product is currently the top-selling item in that category. Lower BSR = more sales.
Example: A BSR of #1,200 in Kitchen & Dining means roughly 1,200 products in that category have sold more than yours in the recent window.
How BSR is Calculated
Amazon does not publish the exact formula, but the key factors are:
- Recent sales velocity (heavily weighted — recent days matter more than older history)
- Historical sales volume (a smoothing factor that prevents a single viral day from producing a misleading BSR)
- Category hierarchy (a product gets BSRs for its primary category and all subcategories)
BSR updates hourly for best sellers and at varying intervals for other products.
What BSR Tells You
| BSR Range | Rough Sales Rate (varies by category) |
|---|---|
| #1–100 | Thousands of units/month |
| #100–1,000 | Hundreds of units/month |
| #1,000–10,000 | Tens of units/month |
| #50,000+ | A few units/month |
These ranges vary enormously by category. A #500 BSR in Pet Supplies means something very different from #500 in Industrial & Scientific.
BSR and Organic Keyword Ranking
BSR and keyword ranking (your position in search results for a keyword) are related but distinct. High BSR in a subcategory is a signal Amazon uses when determining organic keyword ranking — but keyword ranking also depends on relevance, conversion rate, reviews, and PPC spend.
Using BSR for Research
- Validate demand: A consistently low BSR confirms real sales volume.
- Estimate competitor sales: Plug BSRs into sales estimator tools to benchmark how many units/month top competitors sell.
- Track launch progress: Monitor your own BSR daily during a launch to confirm sales velocity is building.