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Reseller ROI Calculator

See actual net profit and ROI on a flip across eBay, Mercari, Poshmark, Whatnot, FB Marketplace, and Etsy. Real fee structures, instant breakdown.

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

Fees are estimates as of April 2026. Real fees vary by category, store subscription, and seller status. Always verify with 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.

Reseller ROI calculator FAQs

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.
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.
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.
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.
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.
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.
They're estimates based on the most common fee tier as of April 2026. Real fees vary by category (eBay's electronics tier is different from collectibles), seller subscription level (eBay Stores get discounts), and seller history (Poshmark sometimes runs promotional fee structures for new sellers). Always verify with the marketplace's current fee schedule before making a sourcing decision worth more than $20.
Reseller ROI Calculator — eBay, Mercari, Poshmark, Whatnot Fees | Item Value Checker