The real costs of Amazon FBA that almost nobody adds up at the start
Many people work out a product’s margin like this: selling price minus purchase price. By that math, almost everything looks profitable. Then Amazon’s settlements arrive and the margin is half what you expected, or gone.
These are the costs worth adding up from day one.
Before the product reaches Amazon
- Product cost at the factory, including samples and any design changes.
- International shipping to the selling country, which varies a lot between sea and air freight.
- Import duties and taxes, which depend on the product and the country.
- Quality inspection, optional but recommended on the first order.
- Labeling and packaging to Amazon’s requirements.
When Amazon sells it for you
- Referral fee: a percentage of the price that depends on the category.
- FBA fulfillment fee: the cost of picking, packing and shipping each order. It depends on size and weight, which is why a small, light product usually leaves more margin.
- Storage: you pay for the space you use, more in peak season, with surcharges if inventory sits in the warehouse too long.
- Seller subscription: a fixed monthly fee on the professional plan.
Exact fees change every year, so always check Amazon’s official calculator for your marketplace before deciding.
The costs no calculator shows
- Advertising. When you launch a product, almost all early sales come from ads. Work out what each sale costs you, not just each click.
- Returns. Some categories, like clothing, have high return rates, and not everything that comes back can be resold.
- Tied-up inventory. Money sitting in idle stock isn’t working for you, and if you overestimate sales you’ll also pay more for storage.
A simple formula for your margin
For each unit sold:
| Item | How to calculate it |
|---|---|
| Revenue | Selling price excluding sales tax or VAT |
| Product cost | Factory + shipping + duties, divided by units |
| Amazon fees | Referral fee + fulfillment fee |
| Advertising | Ad spend divided by units sold |
| Returns reserve | Estimated percentage for the category |
| Margin | Revenue minus everything above |
If the resulting margin leaves no cushion for a price drop or a bad season, better to rule it out now than after you’ve paid for the order.
Why forecasting matters as much as margin
A good margin with bad forecasts also loses money: order too much and you pay for storage; order too little and you run out of stock and lose ranking. That’s why the kit Forecast Your Amazon FBA Sales combines cost calculation with a method for estimating sales before every order.