Free tool · Cratesignal
FBA profit margin, line by line.
Drop in a product’s sale price, landed cost, weight, and package dimensions. The calculator returns Amazon’s referral fee, FBA fulfillment + shipping cost, and monthly storage — plus net profit and margin % — so you can see which fee is eating your margin before you commit to ordering stock.
How the numbers are calculated
Referral fee percentages come from Amazon Seller Central’s published category schedule (15% default, 8% electronics, 17% apparel, plus the $1.80 + 15% books rule and the $0.30 electronics minimum on items below $100). Fulfillment fees are picked from Amazon’s Standard vs. Large Standard vs. Bulky vs. Extra-Large size tiers using your weight and the longest / median / shortest dimensions. Monthly storage is computed as cubicFeet × $/ft³/month × months using the average of Amazon’s off-peak and peak per-cubic-foot rates.
When Amazon publishes a new rate card, update the constants in src/lib/business/fba-fees.ts (look for SCHEDULE_VERSION) and refresh the snapshot in this footer.
For questions or to flag a scheduling issue, write to cratesignal-3@polsia.app.