Finance

Amazon ROI Calculator

Free Amazon ROI calculator — work out return on investment, profit margin, monthly profit, capital tied up and how many months it takes to get your inventory cash back.

Amazon ROI Calculator is a free online finance tool from FastDailyTools (ROI, margin and payback period on your Amazon inventory.). Free Amazon ROI calculator — work out return on investment, profit margin, monthly profit, capital tied up and how many months it takes to get your inventory cash back. It runs entirely in your browser — no sign-up, no account, no email and no upload — and every result can be exported as a dated PDF report.

✔ Price: free, unlimited use, no rate limits
✔ Sign-up: not required
✔ Privacy: all math runs client-side, nothing is uploaded
✔ Export: one-click PDF report (2026 rates)

MarketplaceSelling price ($)Cost per unit ($)Supplier price + inbound freightAmazon fees per unit ($)Referral + FBA + storageUnits sold per monthReturn rate (%)Typical Amazon return rate is 2–8%

Profit per unit

$16.00

After 3% returns

ROI

178%

Strong — 100%+

Profit margin

45.7%

Net margin on price

Sell multiple

3.89×

Price ÷ unit cost (aim 3×)

Monthly profit

$4798.59

300 units

Capital tied up

$2700.00

Inventory purchase cost

Yearly profit

$57583.08

At this run rate

Cash-back cycle

0.6 mo

Months to recover capital

Popular long-tail searches from US users — jump straight to the tool.

How to use Amazon ROI Calculator

Enter your selling price, unit cost and Amazon fees per unit.
Add your monthly unit volume and typical return rate.
Read ROI, margin and profit per unit.
Check capital tied up and how long it takes to recover it.

Frequently asked questions

How do you calculate ROI on Amazon?

ROI = net profit per unit ÷ your cost per unit × 100. If a product costs you $9 landed and nets $9 profit after Amazon fees, that is a 100% ROI.

What is a good ROI on Amazon FBA?

Retail and online arbitrage sellers usually aim for 50–100%+ ROI; private label sellers accept 40–60% because volume is higher and repeat orders are cheaper to source.

What is the difference between ROI and margin?

Margin divides profit by the selling price, ROI divides profit by your cost. A 30% margin can be a 100% ROI — ROI tells you how hard your cash is working, margin tells you how much price cushion you have.

Why does the return rate matter?

Amazon shoppers return 2–8% of orders in most categories (more in apparel). Returns take back the sale but not all fees, so a high return rate silently eats ROI.

How long until I get my inventory money back?

Divide capital tied up by monthly profit — this calculator shows it as the cash-back cycle. Under 3 months is excellent for reselling; over 8 months usually means overbuying.