Enter your costs and selling price to check if this is a profitable flip
Net Profit ($)
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What you keep after all Amazon fees and sourcing costs
Return on Investment (ROI %)
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Net profit measured against your cost of goods
🛒 Your Sourcing Costs and Amazon Selling Details
Sourcing Costs
$
The price you paid in store or online to acquire one unit.
$
Per-unit cost to ship the item into Amazon, plus any labels, poly bags, or prep service fees.
Sales and Platform Fees
$
The price you expect the item to sell for on Amazon, often the Buy Box price.
%
Amazon's category commission on the sale price. 15% is the standard rate for most categories.
$
The flat per-unit fee Amazon charges to pick, pack, and ship a standard-size item.
Reality Check: Where Your Money Goes
Start with gross revenue at the top, then watch the Amazon fees and your sourcing costs come out to arrive at your real net profit.
Gross Revenue (Selling Price)
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Total Amazon Fees (referral plus FBA)
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Your Sourcing Costs (item plus inbound)
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Net Profit Per Unit
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Profit Margin
--
Net profit as a share of selling price
Total Cost of Goods
--
Item cost plus inbound and prep
Break-Even Selling Price
--
Price where net profit hits zero
📖 Key Terms Explained
Retail Arbitrage (RA)
Buying discounted physical products in person from brick-and-mortar stores, such as clearance shelves at big-box retailers, then reselling them on Amazon for a higher price after fees.
Online Arbitrage (OA)
The same buy-low, sell-high model as retail arbitrage, except you source the discounted inventory from online retailers and deal sites instead of walking physical stores.
Fulfillment by Amazon (FBA)
A service where you ship inventory into Amazon's warehouses and Amazon stores, picks, packs, ships, and handles customer service for each sale, in exchange for fulfillment and storage fees.
FBM (Fulfilled by Merchant)
The alternative to FBA, where you store the inventory yourself and ship each order directly to the customer. You avoid FBA fulfillment fees but take on the packing, postage, and service workload.
Referral Fee
The commission Amazon charges on the total sale price of an item, typically 15% for most categories. It is deducted automatically from every sale regardless of whether you use FBA or FBM.
FBA Fulfillment Fee
A flat per-unit charge that covers Amazon picking, packing, and shipping your item to the buyer. It scales with the product's size and weight rather than its price.
Cost of Goods (COGS)
Everything you spent to get one sellable unit into Amazon: the purchase price plus inbound shipping and any prep costs. ROI is measured against this number.
ROI vs. Profit Margin
ROI divides net profit by your cost of goods and shows how hard your cash is working. Profit margin divides the same net profit by the selling price and shows how much of each sale dollar you keep.
Buy Box
The featured offer on an Amazon product page where the Add to Cart button lives. Winning the Buy Box drives the large majority of sales, and its price is usually the realistic selling price to plug into this calculator.
Break-Even Price
The selling price at which your net profit is exactly zero, once referral and FBA fees and your cost of goods are all covered. Sell above it to profit, below it to lose money.

The Complete Guide to Amazon FBA and Retail Arbitrage Profit

A product that costs 15 dollars in a clearance aisle and sells for 45 dollars on Amazon looks like a 30-dollar win, but experienced sellers know that gap is not your profit. Between the referral fee, the FBA fulfillment fee, and your inbound shipping, a sizeable chunk disappears before you ever see a deposit. This guide explains the math behind the arbitrage calculator above, how to read the receipt-style Reality Check, and what numbers actually make a flip worth buying.

How to Use This Arbitrage Calculator

Work left to right. In the Sourcing Costs panel, enter the Cost of Item to You (what you paid per unit) and your Inbound Shipping to Amazon and Prep Costs (per-unit shipping into Amazon plus any poly bags, labels, or prep-service fees). In the Sales and Platform Fees panel, enter your Target Selling Price (usually the current Buy Box price), the Amazon Referral Fee percentage for the category (15% is the standard default), and the flat FBA Fulfillment Fee for the item's size and weight. Everything recalculates instantly as you type, with no submit button to press. The hero shows Net Profit and ROI together, the Reality Check breaks down exactly where your money goes, and the status banner gives you a quick green, yellow, or red verdict.

The Arbitrage Math, Step by Step

First the engine adds your item cost and inbound shipping to get the Total Cost of Goods. Next it calculates the referral fee as a percentage of your selling price, then adds the flat FBA fulfillment fee to get Total Marketplace Fees. The Total Break-Even Cost is your cost of goods plus those marketplace fees combined, which is the all-in amount the sale has to clear before you make a cent. Net Profit is simply the selling price minus that break-even cost. From there, ROI is net profit divided by your cost of goods, and profit margin is net profit divided by the selling price. Every dollar figure is rounded to exact cents using floating-point-safe arithmetic so the receipt always adds up.

A Worked Example

Suppose you buy an item for 15.00 dollars with 1.50 dollars of inbound shipping and prep, giving a Total Cost of Goods of 16.50 dollars. You plan to sell it for 45.00 dollars. The 15% referral fee on 45 dollars is 6.75 dollars, and the FBA fee is 6.50 dollars, so Total Amazon Fees come to 13.25 dollars. Subtract the 13.25 in fees and the 16.50 in sourcing costs from the 45-dollar selling price and you keep 15.25 dollars in net profit. That is a 92% ROI on your 16.50 cost of goods and a 34% profit margin on the sale. Because the ROI clears the 30% threshold comfortably, the status banner flags this as a strong flip.

What Makes a Flip Worth Buying

Most arbitrage sellers will not buy a unit unless it clears at least 30% ROI, and they prefer 50% or higher. That cushion is not greed, it is insurance. A single customer return can erase the profit on several good units, and prices on Amazon can slide quickly when other sellers undercut the Buy Box. Storage fees creep up the longer inventory sits, and fee schedules change. A flip that only nets 10 to 15% ROI has almost no room to absorb any of these surprises, while a 40% ROI flip can take a hit and still come out ahead. Treat the yellow Low Margin warning on this tool as a prompt to look closer at how stable the price and demand really are before committing cash.

Reading the Status Banner and Reality Check

A green Great Flip banner means your ROI is above 30%, the level that meets standard arbitrage profitability goals. A yellow Low Margin Flip banner means you will make money but the cushion is thin, so a return or fee change could wipe out the profit. A red Bad Flip banner means the fees and costs exceed what the item sells for, so you would lose money on every unit. The Reality Check receipt below the hero exists to make one truth obvious: the gross revenue at the top is almost never what you keep. Watch how the Amazon fees and your sourcing costs stack up against that gross figure, and you will quickly build an instinct for which deals are genuinely worth scanning and buying.

Frequently Asked Questions

Both are the same core business model: buying a product cheaply in one place and reselling it for more on Amazon, pocketing the difference after fees. The only difference is where you source the inventory. Retail Arbitrage (RA) means buying physical products in person from brick-and-mortar stores, such as clearance aisles at Walmart, Target, Walgreens, or going-out-of-business sales, then scanning barcodes in the Amazon Seller app to check the resale price. Online Arbitrage (OA) means buying the same kind of discounted inventory from online retailers and deal sites instead, sourcing from your couch rather than driving store to store. RA can surface deals that never appear online and has lower competition per store, but it costs you time and gas. OA scales better, can be partly automated with sourcing tools and lists, and lets you buy in larger quantities, but the deals are visible to thousands of other sellers at once. The profit math, including referral fees, FBA fees, and ROI, is identical for both, which is why this calculator works for either approach.
Amazon takes two main fees on an FBA sale, and together they often add up to 30 to 45 percent of your selling price. The first is the referral fee, a commission Amazon charges on the total sale price. For most categories this is 15 percent, though it ranges from about 8 percent for some electronics up to 17 percent or more for jewelry and certain other categories. The second is the FBA fulfillment fee, a flat per-unit charge that covers Amazon picking, packing, and shipping the item to the customer, and it scales with the product's size and weight, typically running from about 3 to 8 dollars for standard-size items. On top of those, longer-term storage fees, return processing, and optional prep fees can apply. The big mistake new sellers make is looking only at the gap between their cost and the selling price while ignoring these fees. This calculator forces both the referral percentage and the flat FBA fee into the math so the net profit you see is what you would actually keep.
The common rule of thumb among arbitrage sellers is to aim for a minimum of 30 percent ROI, with 50 percent or higher considered a strong flip. ROI, or return on investment, measures your net profit against the cash you tied up in the product (your cost of goods), so a 50 percent ROI means that for every 100 dollars you spent on inventory you cleared 50 dollars in profit after all Amazon fees. Why insist on 30 percent or more? Because that margin is your buffer against the things that go wrong: a customer return, a price war that drops the selling price, an unexpected fee increase, a long-term storage charge, or a unit lost or damaged in Amazon's warehouse. A flip that only nets 10 to 15 percent ROI can be wiped out entirely by a single return. The 30 to 50 percent target leaves enough cushion that your overall portfolio of flips stays profitable even when some individual items underperform. Use the status banner on this tool as a quick green light or warning before you buy.
They both measure profitability but against different denominators, and confusing them is one of the most common beginner errors. ROI (return on investment) divides your net profit by your cost of goods, the money you actually spent to acquire the item. Profit margin divides the same net profit by the selling price, the total revenue the sale brought in. Take an item that costs you 16.50 dollars all-in, sells for 45 dollars, and nets 15.25 dollars after fees. The ROI is 15.25 divided by 16.50, about 92 percent, while the profit margin is 15.25 divided by 45, about 34 percent. ROI answers how hard your cash is working and how fast it can compound as you reinvest, which is why arbitrage sellers obsess over it. Profit margin answers how much of each sale dollar you keep, which matters for pricing strategy and absorbing fee changes. A great flip usually has a high ROI even when the margin looks modest, because cheap sourcing lets you recycle your capital quickly. This calculator shows both so you never have to choose.
No. Every calculation runs entirely inside your own browser using client-side JavaScript. The item cost, shipping and prep costs, selling price, referral percentage, and FBA fee you enter are never transmitted, saved, or shared with any server. Nothing you type leaves your device, so your sourcing numbers and profit strategy stay completely private.