The two fees on every sale
Every FBA sale carries two charges. The referral feeis Amazon's commission — a percentage of the total price the buyer pays. It's 15% in most categories, lower for electronics (around 8%), and higher for a few like jewelry. The fulfillment feeis what Amazon charges to pick, pack and ship the unit; it's a flat per-unit amount set by your product's size and weight.
The trap most new sellers miss: the referral fee has a $0.30 per-item minimum. Amazon charges the greater of the category percentage or $0.30. On a $2 product, 15% is exactly $0.30 — so the floor binds and takes a full 15% of your price no matter what. It's the number-one reason cheap products lose money.
Size tiers decide your fulfillment fee
Amazon sorts every product into a size tier from its dimensions and weight, and the tier sets the fulfillment fee. The broad tiers are:
- Small standard — light, small, thin items (think phone cases, spice jars).
- Large standard — most everyday products that still fit in a standard box.
- Oversize — bulky or heavy items, billed at materially higher rates.
The tiers are defined by threshold dimensions and weights. Crossing one — a box that's a half-inch too tall, a unit an ounce too heavy — can bump you into the next tier and add cost to every single unit you ever ship. Trimming packaging to stay under a threshold is one of the highest-leverage things a seller can do.
Dimensional weight: bulky-but-light gets punished
For anything above the smallest tier, Amazon bills the greater of actual weight and dimensional weight. Dimensional weight is length × width × height ÷ 139. A pillow or a large plastic organizer weighs almost nothing on a scale but takes up real space in a truck, so Amazon charges on the volume. If your product is light and bulky, model the dimensional weight before you assume a low fulfillment fee.
Storage: the fee that runs while you sleep
Referral and fulfillment fees hit when something sells. Storage fees hit every month the inventory sits in a fulfillment center, charged per cubic foot and markedly higher in Q4. Slow movers also accrue aged-inventory surcharges. Overstock quietly compounds: the units you over-ordered pay rent until they sell or you remove them. This is why restock planning and profit tracking matter as much as the per-unit math.
The fees people forget
A few more line items shape your true margin. Refunds carry a refund-administration fee even after the customer is repaid, and returned units may need re-processing or be unsellable. Long-unsold stock can be hit with removal or disposal fees. None are huge individually, but across a catalog they add up — and Amazon periodically loses or mis-charges inventory, which is money you can reclaim if you're tracking it.
How to predict your real margin
You don't have to hold all of this in your head. Put your price, unit cost and box dimensions into a calculator that applies the whole chain — referral rate with the $0.30 floor, size-tier classification, dimensional weight and fulfillment fee — and it returns your net profit, margin, ROI and break-even price before you spend on inventory.
Fee percentages and thresholds are described in structural terms because Amazon revises the exact figures periodically — the calculators carry the current numbers.
FAQ
How much does Amazon take per sale?+
On a typical sale you pay two fees: a referral fee (a percentage of the total sale price — 15% in most categories, lower for electronics, higher for jewelry) and an FBA fulfillment fee (a flat per-unit charge based on your product's size tier and weight). On cheap items a $0.30 referral-fee minimum also applies. Storage and the occasional refund or removal fee sit on top.
What is the $0.30 referral minimum and why does it matter?+
Amazon charges the greater of the category percentage or $0.30 per item as the referral fee. On a $2 item, 15% is only $0.30 — so the minimum binds and quietly eats 15% of your price. It's the single most overlooked reason low-priced products lose money.
What is dimensional weight?+
For anything above the smallest tier, Amazon bills the greater of your item's actual weight and its dimensional weight — length × width × height ÷ 139. Bulky-but-light products (pillows, large plastics) get charged on their volume, not their scale weight, which can push the fulfillment fee up sharply.
How do I know my fees before I buy inventory?+
Enter your price, cost and box dimensions into a free FBA calculator. A good one applies the real referral rate (with the $0.30 floor), classifies the size tier, computes dimensional weight, and returns your net profit, margin and break-even price — before you commit a dollar to sourcing.