Amazon FBA profit & break-even ACOS calculator (US)
Before you launch or advertise a product, know the numbers that decide whether it works: what you actually keep per unit after Amazon's fees and your costs, your margin and ROI, and the break-even ACOS that tells you how much you can spend on ads per sale. Enter your own figures — nothing is hard-coded, and nothing leaves your browser.
You keep $7.79 per unit — a 26.0% margin and 101.2% ROI.
Your numbers
- Net profit / unit
- $7.79
- Margin
- 26.0%
- ROI
- 101.2%
- Break-even ACOS
- 36.0%
- Amazon fees
- $10.00
- Break-even price
- $17.29
You keep $7.79 per unit — a 26.0% margin and 101.2% ROI.
“Email me my result” opens your own email app with the numbers filled in — we don't see or store them.
How it's worked out
- Referral fee= selling price × your category's referral %.
- Net profit = selling price − (referral + FBA fees) − (product cost + inbound + other) − advertising.
- Margin = net profit ÷ selling price. ROI = net profit ÷ (product cost + inbound shipping) — the cash you put in.
- Break-even ACOS = profit before ads ÷ selling price — the most you can spend on ads per sale and still break even.
- Break-even price = (FBA fee + your costs) ÷ (1 − referral %) — the price at which profit before ads is zero.
These are estimates from the figures you enter. Amazon's exact fees depend on your category and size tier, and refunds, storage and returns vary month to month — use your own recent numbers for the truest picture.
Profit questions Amazon US sellers ask
What is break-even ACOS?
The advertising cost of sale at which an ad-driven order makes no profit and no loss. It equals your profit before advertising divided by the selling price: if a unit makes $6 of profit before ads on a $30 price, break-even ACOS is 20% — spend up to 20% of that sale on ads and you still break even. Below it you profit on the ad; above it you lose money on the ad.
Where do I find my referral fee and FBA fee?
Both are in Seller Central. The referral fee is a percentage set by product category (commonly 8–17%, often 15%). The FBA fulfillment fee is a fixed amount per unit based on the item's size and weight tier. We do not hard-code either — you enter your own so the result is correct for your exact product, and stays correct when Amazon changes its rates.
What is the difference between margin and ROI?
Margin is profit as a percentage of the selling price (how much of each dollar of revenue you keep). ROI is profit as a percentage of the cash you put in per unit — product cost plus inbound shipping — so it answers how hard your money is working. A low-priced item can have a thin margin but a high ROI, or the reverse.
Does this send my numbers anywhere?
No. The calculation runs entirely in your browser — nothing you type is sent to us or to any server. The only thing that ever leaves your browser is the early-access email, if you choose to join the list.
Why is my profit negative?
At the numbers entered, the selling price does not cover Amazon's fees plus your product cost, inbound shipping, other costs and advertising. Raise the price, lower a cost, or check the break-even price the calculator shows — the selling price at which profit before ads reaches zero.
Related free tools
- Settlement report analyser — reconcile a real payout and see per-SKU profit from your own report.
- Settlement profit calculator — what a settlement really leaves you after fees, refunds and ads.
- Reorder-point & safety-stock calculator — when to send your next FBA shipment and how many units.
- Where is my FBA stock, and what does it trigger? — which states want you registered for sales tax.
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