How the FBA vs FBM Calculator works
FBA charges a fulfillment fee and storage but gives you Prime and hands-off logistics. FBM avoids those fees but you pay the carrier, packaging and labor, and you usually convert worse without Prime. This tool compares the pure per-unit economics.
Formula
- FBA profit = Price − Cost − Inbound shipping − Prep − Referral − FBA fee − Storage − Ads − Returns
- FBM profit = (Price + Shipping charged) − Cost − Referral − Carrier − Packaging − Labor − Warehouse − Ads − Returns
Example
Heavier items often favor FBM when you have a cheap carrier rate; light items almost always favor FBA.
Selling price: 49.99Amazon category: home_kitchenProduct cost (per unit): 15Unit weight (lb): 4Length (in): 14Width (in): 10Height (in): 6Carrier cost to customer: 9.5
Frequently asked questions
Does the calculator include the Prime conversion lift?
No. It compares costs only. Many sellers see 20–50% higher conversion with Prime, which can outweigh a small FBM cost advantage.