About MarginSolver

Our mission

Between 2024 and 2026–2027, major e-commerce platforms altered their fee architecture. Amazon introduced Inbound Placement Service Fees, Low-Inventory-Level surcharges, updated dimensional weight rounding rules, and tiered referral thresholds. While large SaaS enterprise suites locked these fundamental calculations behind $100+/month subscriptions and mandatory email capture walls, MarginSolver was built to provide instant, client-side, 100% free mathematical models accessible to every entrepreneur.

How we verify fee schedules

Our calculation models are audited continuously against official carrier documentation and seller announcements:

• Official Amazon Seller Central announcements: We track fee schedule notices, program policy changes, and category referral updates published by Amazon Services.
• Volumetric & carrier divisor standards: We reflect standard domestic dimensional weight divisor rules (Divisor 139) and size tier thresholds across small standard, large standard, and bulky classifications.
• Low-Price FBA thresholds: We automatically track and apply the $0.77 unit fulfillment fee discount for items priced below $10.00.

Editorial independence & monetization

MarginSolver is completely free to use. We do not sell your email, require account registrations, or gate calculations behind paywalls. To sustain our server infrastructure and ongoing fee research, our platform is funded by clean, privacy-compliant display advertising and optional software referral partnerships.

Important disclaimer

MarginSolver is an independent research entity and is NOT affiliated, endorsed, or sponsored by Amazon.com, Inc., Shopify Inc., or any of their affiliates. Amazon, Fulfillment by Amazon, FBA, Prime, and associated marks are registered trademarks of Amazon.com, Inc. Calculations are estimates provided for modeling purposes; always verify exact rates in your official seller portal.