Hi, I am happy to answer this question for you. The FBA calculator is an essential tool for an Amazon seller to understand the Amazon FBA fees, compare fulfillment methods. The Amazon FBA calculator is also an excellent tool to understand the product profitability to analyze if a product is worth the efforts and money. How to use the Amazon FBA calculator next? I would recommend a extension that I am using myself called 4seller. Its calculator function can help you quickly calculate the profit and cost of a product on Amazon, including calculating FBA fees.