Amazon ROI Calculator

Amazon ROI measures profit against the cash you tied up, not against the sale price. Take a product selling at $35.00 that costs $8.00 landed and pays a $5.25 referral fee (15%) plus a $5.50 FBA fulfillment fee: net profit is $16.25 per unit. That is a 203.13% ROI on the $8 you actually risked, but only a 46.43% margin on the $35 the buyer paid. Buy 100 units and you commit $800.00 to make $1,625.00. Sell through in 3 months and the same $800 turns 4 times a year, for an annualised return of 812.5%. Those are the numbers the Amazon ROI Calculator returns on its default inputs, and the last one is what actually decides which products deserve your money.

Margin tells you how much of a sale price you keep. ROI tells you how hard your bank balance is working. Since the only real constraint on an Amazon business is how much inventory you can afford to buy, ROI is the metric that ranks decisions — and once you multiply it by inventory turns, it usually ranks them differently than margin does.

Why ROI beats margin when you are buying inventory

The two ratios use the same profit but different denominators:

Margin = net profit ÷ selling price ROI = net profit ÷ cash invested

Amazon's fees come out of the buyer's payment rather than your bank account, so the cash you invest is far smaller than the revenue: $8.00 at risk against $35.00 of sale price, which is why ROI here is over four times the margin.

The two are linked by a clean identity — ROI equals margin divided by cost as a fraction of price. On the same unit: 46.43% ÷ (8 ÷ 35) = 203.13%. Two products with identical margins diverge sharply on ROI if one costs 20% of its price to buy and the other 40%.

That is why margin and ROI rank the same catalogue differently. All five products below carry a 15% referral fee, and every figure matches what the calculator returns:

Product	Price	Landed cost	FBA fee	Referral	Net profit	Margin	ROI
Phone stand	$18.00	$3.50	$4.20	$2.70	$7.60	42.22%	217.14%
Kitchen scale	$35.00	$8.00	$5.50	$5.25	$16.25	46.43%	203.13%
Supplement, 90ct	$60.00	$18.00	$3.50	$9.00	$29.50	49.17%	163.89%
Desk lamp	$48.00	$19.00	$7.30	$7.20	$14.50	30.21%	76.32%
Stand mixer	$220.00	$96.00	$23.00	$33.00	$68.00	30.91%	70.83%

Rank by margin and the supplement wins at 49.17%. Rank by ROI and it drops to third, behind an $18 phone stand with a 42.22% margin. The reason is the denominator: $18 of cash per supplement unit against $3.50 per phone stand. With $3,600 of buying power you can hold 200 supplement units earning $5,900, or 1,028 phone stands earning $7,813 — same cash, 32% more profit, from the product with the worse margin.

The stand mixer makes the point in reverse: its $68.00 profit per unit is the largest in the table and the worst use of cash on the list, because each sale ties up $96 you cannot deploy anywhere else.

The Amazon ROI formula

Four steps, and the calculator runs them in this order.

1. Referral fee = selling price × referral % (minimum $0.30) 2. Total Amazon fees = referral fee + FBA fulfillment fee 3. Cash invested per unit = landed unit cost + other per-unit costs 4. Net profit = selling price − cash invested − total Amazon fees ROI % = net profit ÷ cash invested × 100

Then the time dimension:

Inventory turns per year = 12 ÷ months to sell through Annualised ROI % = ROI % × turns per year

Amazon applies a $0.30 minimum referral fee per item (2026 US rule), which only binds on very cheap units — at a 15% rate it takes over below a $2.00 selling price.

The critical modelling choice is in step 3. Referral and FBA fees are not part of the investment base: Amazon takes them out of the buyer's payment, so they never sit on your credit card and never limit how much stock you can buy. Including them in the denominator, as some ROI calculators do, turns the 203.13% above into 86.67%. Both numbers are arithmetically valid; only one answers the question "how much profit does each dollar of my buying power produce?"

A worked example, line by line

These are the calculator's default inputs, worked through in full so you can reproduce every figure.

Line	Value
Selling price	$35.00
Referral fee (15% of $35.00)	−$5.25
FBA fulfillment fee	−$5.50
Total Amazon fees per unit	$10.75
Landed unit cost	−$8.00
Other costs per unit	−$0.00
Cash invested per unit	$8.00
Net profit per unit	$16.25
ROI	203.13%
Margin	46.43%
Units purchased	100
Total cash invested	$800.00
Total profit	$1,625.00
Months to sell through	3
Inventory turns per year	4.0
Annualised ROI	812.5%
Break-even selling price	$15.88

Two figures deserve a second look. $800.00 is the number your bank account cares about — not $3,500 of retail value, not $1,075 of fees, just the cash that leaves you before a single unit sells. And 812.5% is the number that makes this a good buy rather than merely a profitable one: the same $800 comes back and goes out again four times in twelve months.

Inventory turns: the multiplier most sellers ignore

Per-unit ROI is only half a decision. The other half is how often you get that cash back to spend again.

A 30% ROI product that turns 4 times a year returns 120% annually. A 60% ROI product that turns once returns 60%. The second product looks twice as good on every sourcing spreadsheet and delivers half the annual return on the same money.

Here is the full grid. Read down for per-unit ROI, across for turns, and every cell is simple annualised ROI — exactly what the calculator reports.

ROI per turn	1 turn (12 mo)	2 turns (6 mo)	3 turns (4 mo)	4 turns (3 mo)	6 turns (2 mo)	12 turns (1 mo)
20%	20%	40%	60%	80%	120%	240%
30%	30%	60%	90%	120%	180%	360%
40%	40%	80%	120%	160%	240%	480%
50%	50%	100%	150%	200%	300%	600%
60%	60%	120%	180%	240%	360%	720%
75%	75%	150%	225%	300%	450%	900%
100%	100%	200%	300%	400%	600%	1,200%
150%	150%	300%	450%	600%	900%	1,800%

A 20% ROI on a monthly turn (240%) beats a 100% ROI on a two-turn cycle (200%). A 40% ROI product that sells in 4 months matches a 120% ROI product that takes a year. Once you internalise the grid, the sourcing question stops being "what is the ROI?" and becomes "what is the ROI and how fast does it sell?"

This is also the honest defence of low-ROI wholesale. A 25% ROI looks unsellable next to arbitrage numbers, but at a six-week sell-through it annualises to 216% — and it is repeatable, which arbitrage rarely is.

What reinvesting actually compounds to

The calculator reports simple annualised ROI: per-unit ROI multiplied by turns, which assumes you take the profit out. Reinvest it into the next buy and the real return compounds higher.

ROI per turn	Turns/yr	Simple annualised	$10,000 after 1 year, reinvested	Compounded return
60%	1	60%	$16,000	60.00%
40%	2	80%	$19,600	96.00%
30%	3	90%	$21,970	119.70%
30%	4	120%	$28,561	185.61%
25%	4	100%	$24,414	144.14%
20%	6	120%	$29,860	198.60%
15%	12	180%	$53,503	435.03%

The bottom row is the extreme case: a 15% ROI, which almost every sourcing guide would tell you to reject, compounds to 435% a year if the product genuinely sells out monthly and you put everything back in. The gap between the two columns widens with turns, so simple annualisation undervalues fast movers and not slow ones.

Treat the compounded column as an upper bound — it assumes you can rebuy the same deal at the same price, never go out of stock, and withdraw nothing. The principle behind investment ROI applies here unchanged: frequency of return matters as much as size of return.

What belongs in "cash invested" — and what does not

The denominator is where most ROI calculations go wrong, and it always goes wrong in the same direction: too low, which flatters the result.

Cash invested = every dollar you spend to get one sellable unit into an Amazon fulfillment centre. Nothing else. Here is that $8.00 landed cost taken apart:

Cost line	Per unit	In the investment base?
Supplier unit price	$5.90	Yes
Sea freight and customs clearance	$0.95	Yes
Import duty	$0.44	Yes
Prep, poly bag, FNSKU label	$0.35	Yes
Inbound shipping to the fulfillment centre	$0.36	Yes
Landed cost per unit	$8.00	—
Referral fee	$5.25	No — taken from the buyer's payment
FBA fulfillment fee	$5.50	No — taken from the buyer's payment
Monthly storage	varies	No — billed later, reduces profit
PPC advertising	varies	No — billed later, reduces profit

The test is simple: did the money leave your account before the unit sold? If yes, it belongs in the denominator. If Amazon nets it out of your disbursement afterwards, it belongs in the profit calculation only.

Drop the freight, duty and prep and that $8.00 becomes $6.80 — and the reported ROI jumps from 203.13% to 256.62%. A 53-point error, purely from a denominator that ignores costs you genuinely paid. Work out your true landed number with the Landed Cost Calculator first, especially on imported goods where duty and freight can be 15% of the unit cost. If you track prep and inbound separately from the supplier invoice, put them in the calculator's other costs per unit field — it is added straight to the investment base, so the result is identical either way.

What is a good ROI on Amazon? Benchmarks by sourcing model

There is no universal threshold, because the answer depends on how fast the model turns and how much of your time it consumes. These are the rules of thumb Amazon sellers actually use, with the annualised consequence of each:

Sourcing model	Common minimum ROI	Months to sell	Turns/yr	Simple annualised ROI
Retail arbitrage	100%	1.5	8.0	800%
Online arbitrage	75%	2.0	6.0	450%
Wholesale	30%	2.5	4.8	144%
Private label	60%	4.0	3.0	180%
Liquidation pallets	150%	6.0	2.0	300%

The 100% ROI rule on retail arbitrage — double your money or walk away — is not arbitrary. Arbitrage buys are one-off, so every unit costs sourcing labour that never amortises, and the listing price can collapse before you sell through. The high bar pays for that risk and that time.

Private label sits at 50–75% because the buy is repeatable and the listing is yours, but you carry launch advertising, photography, samples and inventory risk on a much larger order. Under 50%, there is no room left to defend the listing with PPC.

Wholesale routinely clears at 25–40% and is still a good business, because the same SKU can be reordered indefinitely and the sourcing work is done once. That is the whole case for the model: low ROI, high turns, low labour.

Two adjustments before applying any of these. They are gross of advertising — spend $2.20 a unit on PPC and the default product's profit falls from $16.25 to $14.05, its ROI from 203.13% to 175.63%. And they assume you sell through; a 100% ROI on the 80% of units that sold is not a 100% ROI on the buy. Sanity-check the unit economics first in the Amazon FBA Profit Calculator, and if fulfillment is still undecided, FBA vs FBM compares the cost structures directly.

How storage fees and aged-inventory surcharges quietly cut your ROI

FBA storage is billed monthly against the cubic footage your inventory occupies, so it is a cost that grows the longer a buy sits. 2026 US standard-size rates are roughly $0.78 per cubic foot per month from January to September and $2.40 from October to December, plus an aged-inventory surcharge from 181 days that escalates each month: about $0.50 per cubic foot at 181–210 days, rising through $0.80 at 241–270 days to $1.40 at 331–365 days, with a much steeper charge beyond a year. Check Amazon's current fee schedule before relying on the exact figures.

Here is what that does to the default product, assuming each unit occupies 0.15 cubic feet and is stored at the January–September rate:

Months held	Base storage	Aged surcharge	Total storage	Profit per unit	ROI	Annualised ROI
1	$0.12	—	$0.12	$16.13	201.63%	2,419.5%
3	$0.35	—	$0.35	$15.90	198.75%	795.0%
6	$0.70	—	$0.70	$15.55	194.38%	388.8%
9	$1.05	$0.29	$1.34	$14.91	186.38%	248.5%
12	$1.40	$0.83	$2.23	$14.02	175.25%	175.25%

Read the last two columns together. Twelve months of storage costs $2.23 a unit — 13.7% of the profit, annoying but survivable. Over the same period annualised ROI falls from 2,419.5% to 175.25%, a 93% collapse. The storage fee is not the problem; it is the invoice that tells you about the problem, which is that your cash spent a year in a warehouse.

Two practical notes. Q4 storage costs roughly three times the off-season rate — $0.36 a month on this unit against $0.12 — so holding non-seasonal stock through October to December is expensive. And bulky items scale badly: a unit at 1.0 cubic feet pays $0.78 a month, which against a $16.25 profit is real money by month six. This is one of several costs that never appear in a sourcing spreadsheet; the hidden costs that eat ecommerce profit covers the rest.

Why a high-ROI slow mover can still bankrupt you

ROI says nothing about when the money comes back, and a business dies from timing long before it dies from margin. Compare two sellers with the same $10,000 and opposite strategies, with profit fully reinvested at each turn:

Point in the year	Seller A — 100% ROI, 12-month sell-through	Seller B — 30% ROI, 3-month sell-through
Start	$10,000 deployed	$10,000 deployed
End of month 3	$0 free, all in stock	$13,000
End of month 6	$0 free, all in stock	$16,900
End of month 9	$0 free, all in stock	$21,970
End of month 12	$20,000	$28,561
Profit for the year	$10,000	$18,561
Chances to restock	1	4
Chances to correct a bad buy	0	3

Seller A's per-unit ROI is 3.3 times better and the year's profit is 46% worse. Worse still, Seller A has zero free cash for eleven months. Add $1,800 a month of fixed costs — software, a VA, storage, insurance — and Seller A pays out $19,800 across a year in which the business generated nothing until December. That is the mechanism that kills profitable Amazon businesses: not losses, but a positive P&L attached to an empty bank account.

There is a second, quieter cost in the last row. Seller B gets three opportunities to notice a mistake and redeploy into something better. Seller A finds out in month twelve. High-ROI slow movers concentrate both your cash and your learning into a single annual bet.

The practical guardrails: keep a cash reserve outside inventory, cap what any single slow-moving SKU can absorb, and treat "months to sell through" as a hard input rather than an optimistic guess. If seasonal buys tie up cash for most of the year, model the fixed costs they have to carry with the Break-Even Calculator.

The break-even selling price you must clear

Break-even is the price where profit is exactly zero. Because the referral fee is a percentage of price, you cannot just add up costs — the fee moves when the price moves, so you have to solve for it:

Break-even price = (cash invested + FBA fee) ÷ (1 − referral %)

On the default product: ($8.00 + $5.50) ÷ 0.85 = $15.88. Check it — a 15% referral on $15.88 is $2.38, so fees total $7.88, and $15.88 − $8.00 − $7.88 = $0.00. The same rearrangement gives you the price for any ROI target, by replacing cash invested with cash invested × (1 + target ROI).

Cash invested	FBA fee	Break-even price	Price for 50% ROI	Price for 100% ROI
$4.00	$3.99	$9.40	$11.75	$14.11
$8.00	$5.50	$15.88	$20.59	$25.29
$12.00	$7.30	$22.71	$29.76	$36.82
$20.00	$9.00	$34.12	$45.88	$57.65
$35.00	$12.00	$55.29	$75.88	$96.47

All rows use a 15% referral fee. Two things fall out of the table. Your break-even is always well above cost plus fees — on row two, $15.88 against $13.50 of direct cost, because the referral fee applies to the price you are trying to solve for. And the gap between break-even and a 100% ROI price is roughly your invested cash grossed up: $15.88 to $25.29 is $9.41 of headroom on $8.00 of cost.

Use break-even as your floor in a price war. If a competitor drops to $18.00 on the default product you still make $5.55 a unit at a 69.38% ROI; at $16.00 you are making $0.10 and should stop. Sellers on other channels can run the same logic with the Marketplace Fee Comparison Calculator, since referral rates differ by platform, or check what a discount does to margin with the Discount Margin Calculator.

How to rank purchase decisions when cash is limited

With unlimited money you buy everything profitable. With a fixed budget, every buy you fund is a buy you did not fund, and the correct ranking key is annualised ROI, not ROI.

Four deals, each needing $1,500, and a $4,500 budget — so exactly three get funded:

Deal	Cash	ROI	Months to sell	Turns/yr	Annualised ROI	Year-1 profit
A — clearance arbitrage lot	$1,500	120%	3.0	4.0	480%	$7,200
B — wholesale restock	$1,500	42%	2.0	6.0	252%	$3,780
C — private label reorder	$1,500	65%	4.0	3.0	195%	$2,925
D — seasonal decor buy	$1,500	190%	10.0	1.2	228%	$3,420

Rank by per-unit ROI and you fund D (190%), A (120%) and C (65%), for $13,545. Rank by annualised ROI and you fund A, B and D, for $14,400 — $855 more, 6.3% better, on identical cash and identical risk. The deal that changes hands is instructive: the "respectable" 65% private label reorder gets dropped for a 42% wholesale restock, purely because the wholesale cash comes back six times a year instead of three.

A working process:

1. Compute per-unit ROI for every candidate in the Amazon ROI Calculator.
2. Attach an honest months-to-sell figure — from your own history on that SKU, not the best case.
3. Multiply to get annualised ROI and sort the list descending.
4. Set a floor and delete everything below it. Under about 100% annualised, the buy is not paying for the labour and risk of managing it.
5. Fund from the top until the cash runs out, but leave a reserve — a fully deployed balance cannot restock a winner.
6. Re-rank after every sell-through, using what actually happened rather than what you projected.

Step 6 is the one that compounds. Sell-through estimates are where sourcing spreadsheets lie, and the only fix is feeding real dates back in. If advertising is part of how a SKU sells, pair this with the Breakeven ROAS Calculator so ad spend is capped by unit economics rather than by hope, and set prices deliberately using how to price products for profit.

Common mistakes

Dividing profit by the selling price and calling it ROI. That is margin. On the default product the difference is 46.43% against 203.13% — the same $16.25, two denominators, and only one of them tells you how many units your bank balance can support.

Putting Amazon's fees in the investment base. Referral and FBA fees come out of the buyer's payment, so they never constrain your buying. Including them turns 203.13% into 86.67% and makes every SKU look half as good. Fees reduce profit; they are not capital you deployed.

Leaving prep and inbound freight out of the cost. Using the supplier invoice alone, $8.00 becomes $6.80 and ROI reads 256.62% instead of 203.13%. Freight, duty, prep, labels and inbound shipping all left your account before the sale, so all of them belong in the denominator.

Judging a buy on ROI alone, with no sell-through time. A 60% ROI on a 12-month turn returns 60% a year. A 30% ROI on a 3-month turn returns 120%. Without months-to-sell, the ROI number is not a decision — it is half of one.

Booking PPC as a per-unit cost in the investment base. Advertising is billed around the time of the sale, not months before it, so it should reduce profit rather than raise the cash you tied up. At $2.20 a unit, treating it correctly gives 175.63%; folding it into "other costs" gives 137.75% and understates how hard your capital is working.

Assuming the whole buy sells. Sell 85 of 100 units and profit is $1,381.25, but $120.00 of cash is still sitting in unsold stock. Real ROI on the $800 is 157.66%, not 203.13% — before any removal or disposal fee. Always model ROI on the buy, not on the units that happened to sell.

Related calculators

• Amazon FBA Profit Calculator — full fee breakdown and profit per unit before you run the ROI
• Landed Cost Calculator — build the true per-unit cost that goes into the investment base
• Profit Margin Calculator — the margin side of the same numbers, for pricing decisions
• Break-Even Calculator — how many units a buy must sell to cover fixed costs
• Breakeven ROAS Calculator — the most you can spend on ads before a SKU stops paying
• Marketplace Fee Comparison — how Amazon's referral rate compares with eBay, Etsy, Walmart and Shopify
• Investment ROI Calculator — the same annualised-return logic applied outside inventory