Amazon FBA vs FBM: Profit Comparison Guide — Which Fulfillment Method is Better?
One of the most common questions new Amazon sellers face is whether to use FBA (Fulfillment by Amazon) or FBM (Fulfillment by Merchant). The answer depends on your product category, price point, and sales volume. Below we break down the costs, tradeoffs, and profit implications of each method using real data from our profit calculator.
FBA vs FBM at a Glance
| Factor | FBA | FBM |
|---|---|---|
| Fulfillment fees | $4.50–$8.00 per unit (standard size) | $3–$6 per unit (shipping + supplies) |
| Storage fees | Monthly per cubic foot (seasonal) | Your own or 3PL storage costs |
| Prime badge | Yes — automatic Prime eligibility | No — unless using SFP (Sellers Fulfilled Prime) |
| Customer service | Amazon handles returns and support | You handle returns and support |
| Return rate impact | Amazon charges referral fee even on returned items | Same — referral fee is non-refundable |
| International selling | Amazon handles cross-border logistics | You manage international shipping yourself |
| Best for price range | Products above $20 | Products under $20 |
Cost Breakdown by Fulfillment Method
The fee difference between FBA and FBM is often the deciding factor. Let's look at how costs stack up for a typical $24.99 product in the US marketplace.
FBA Costs for a $24.99 Product (1 lb, standard size)
- Fulfillment fee: $5.15 (standard size, 1 lb)
- Monthly storage fee: $0.15 per unit
- Referral fee (15%): $3.75
- Advertising (15% ACoS): $3.75
- Return loss (5%): $1.25
- Total fees: ~$14.05 per unit
FBM Costs for the Same $24.99 Product
- Outbound shipping: $4.50 (USPS Ground Advantage)
- Pick & pack: $1.00 per unit
- Monthly 3PL storage: $0.50 per unit
- Referral fee (15%): $3.75
- Advertising (15% ACoS): $3.75
- Return loss (5%): $1.25
- Total fees: ~$14.75 per unit
In this example, FBA and FBM are nearly identical in total fees. But the balance shifts dramatically based on product size, weight, and price point.
When to Choose FBA
- Products priced above $25 where fulfillment fees are a smaller percentage of revenue
- Small, lightweight items that qualify for low FBA fees
- Products in competitive categories where the Prime badge drives conversion
- Sellers who want to scale without managing logistics
For example, a product like wireless earbuds at $29.99 benefits from FBA because the Prime badge increases conversion rates by 15-25% in competitive categories.
When to Choose FBM
- Products under $20 where FBA fees consume too much margin
- Heavy or oversized items with high dimensional weight fees on FBA
- Products with very low return rates (<3%)
- Sellers who already have a 3PL relationship with better rates
For example, board games (typically 1.5 lbs at $29.99) often perform better with FBM because dimensional weight pricing makes FBA expensive for box-shaped items.
Use our free profit calculator to model both FBA and FBM scenarios with your actual product dimensions and costs.