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Reseller ROI Calculator

Estimate net profit and ROI on a flip across eBay, Mercari, Poshmark, Whatnot, Facebook Marketplace, and Etsy using common fee tiers.

Your numbers

Quick start — try a preset

~13.25% + $0.30/order (most categories)

$

What you paid for the item

$

What the buyer pays for the item

$

$0 if free shipping. Most marketplaces charge fees on this too.

$

What you pay for the label

$

Box, tape, supplies, gas to thrift, etc.

Net profit

$20.74

ROI: 207.4%
Margin: 46.1%

Breakdown

Gross revenue (sale + shipping)
$45.00
− Cost basis
-$10.00
− Shipping cost
-$8.00
− Other costs
-$0.00
− eBay fees

13.25% × $45.00 + $0.30 = $6.26

-$6.26
Net profit
$20.74

These are simplified estimates, not marketplace quotes. Whatnot's standard U.S. schedule was checked in July 2026; other marketplace tiers were not independently re-verified in this update. Rates can vary by category, region, promotion, subscription, and seller status. Whatnot processing here excludes buyer tax and any tax on Whatnot fees because those amounts are not entered. Always verify the marketplace's current fee schedule.

Why ROI matters more than gross sales

Two resellers can do $5,000/month in gross sales and have wildly different bank balances. The one tracking ROI knows which sourcing trips paid off and which were a wash; the one looking only at top-line sees the same number every month and can't explain why their savings aren't growing.

The classic trap: a $40 sale on eBay with $8 shipping cost and $1.50 packing supplies. After the 13.25% fee on $48 ($6.36) and the $0.30 per-order fee, you've spent $16.16 in costs against $48 of revenue. If you bought it for $5, that's $26.84 profit — a 537% ROI. Great trip.

But change the numbers slightly: same $40 sale, but you bought it for $25 and shipping is $12 (heavier item). Now you have $39.66 in costs against $48 of revenue. $8.34 profit. 33% ROI. Same gross, vastly different outcome. Without the calculator, both look like "a $40 sale" in your spreadsheet.

Used together with our other free tools

Photo Value Checker

Get the sell-price estimate before you calculate ROI.

AI Listing Generator

Once you decide to flip it, generate the listing copy.

Bulk Value Checker

Triage a whole haul before doing the ROI math one by one.

Whatnot Fee Calculator

See commission, processing, shipping, and tax caveats.

Reseller ROI calculator FAQs

How do I calculate ROI on a reseller flip?
ROI = (sell price − cost basis − shipping − fees − other costs) ÷ cost basis × 100. So a $10 thrift find that nets $30 profit after all costs is 300% ROI. Margin is different: profit ÷ gross revenue. Most resellers track ROI for sourcing decisions and margin for pricing decisions.
Why does my eBay fee seem higher than 13%?
eBay charges the final-value fee on the entire buyer payment, including shipping. So a $50 item with $10 shipping incurs the 13.25% on $60, not $50. Plus the $0.30 per-order fee. Free shipping doesn't avoid this — you just bake the shipping into the item price and pay fees on the bigger number.
Is Poshmark really 20%?
Yes for sales over $15. Sales of $15 or less are a flat $2.95. So a $14 sale costs you 21% in fees ($2.95/$14), but a $15.01 sale only costs 20% — there's a small dip right at the threshold. Pricing items between $13-15 is usually a mistake.
What about Mercari's payment fee?
Mercari charges 10% as a selling fee, then a separate 2.9% + $0.50 payment processing fee on the total (item + shipping the buyer pays). On a $30 item with $5 shipping that's $3.50 selling + $1.51 processing = $5.01 in total fees, or 14.3% effective.
How are Whatnot seller fees calculated?
For most standard U.S. categories, Whatnot charges 8% commission on the item's final sale price plus 2.9% of the buyer's total order value and $0.30 for payment processing. The processing basis normally includes buyer-paid shipping and tax. This calculator can include shipping, but it excludes buyer tax and any tax charged on Whatnot fees because those amounts are not entered.
Why is local Facebook Marketplace 0% fees?
FB Marketplace only charges fees when shipping is involved (5% with $0.40 minimum). Local pickup transactions are 100% yours. This is one of the highest-margin marketplaces if you can find local buyers — just account for the time cost of meeting up.
What costs am I forgetting?
The big ones beyond marketplace fees: packing supplies (boxes, tape, poly mailers — about $0.50-2 per shipment), sourcing time and gas (allocate $5-10 per haul), photo time, listing time, and your hourly rate. Hobbyists often ignore these; full-time resellers track every minute.
How accurate are these fee calculations?
They're simplified estimates, not marketplace quotes. Whatnot's standard U.S. schedule was checked in July 2026; the other marketplace tiers were not independently re-verified in this update. Fees vary by category, region, promotion, seller subscription, and tax treatment. The calculator also cannot know buyer tax unless a marketplace exposes it before the sale. Always verify the marketplace's current fee schedule before making a sourcing decision.

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Reseller ROI Calculator — eBay, Mercari, Poshmark, Whatnot Fees