2027 Reseller Spreadsheet Inventory and Profit Tracker for eBay Poshmark Mercari Depop | Fee Calculator, COGS, Sell Through, Schedule C Tax

Know what it made, after every fee.

A thrift haul goes out on five apps, the payouts land in three accounts, and at the end of the month you know what you sold and not what you made. Then April arrives and the shoebox has the mailers, the storage unit, the labels, the fees you never saw, and a hundred items that were never really inventory because they never sold. This file costs every item once, nets every sale after the platform's fee and the label, ages what is still sitting, and puts every dollar on its Schedule C line as you go.

THREE THINGS TO KNOW BEFORE YOU BUY

I only sell on eBay. One platform is one row. The fee engine ships with eBay, Poshmark, Mercari, Depop, Whatnot and a local cash row already filled in at their published US rates, and every rate is a cream cell you can change the day a platform changes it.

I am not a spreadsheet person. You type in the cream cells only: the SKU and what you paid on the day you buy it, then the platform, the price, the shipping charged and the label when it sells. Every other cell is a formula, 10,438 of them. The fee, the payout, the profit, the margin, the days sitting, the aging flags and the Schedule C lines are read, never typed.

Will my CPA use it? It reads like the form. Schedule C, Part I lines 1 to 7, Part II lines 8 to 31, and Part III lines 33 to 42, with cost of goods sold built from your own shelves: beginning inventory, purchases less items withdrawn for personal use, ending inventory.

WHAT IS INSIDE (10 TABS)

• Start Here, three steps and you are costing items
• Setup, your platforms and their fees once: the item fee and whether it applies to shipping, the per-order fee, payment processing, a flat fee under a threshold, and whether the buyer pays the label; plus your stale and death-pile day counts, your set-aside percentage, the 1099-K thresholds and the two 2026 mileage rates
• Inventory, one row per item: SKU, what you paid, prep, source, category, listed date and price, then status, days sitting and a FRESH, Stale or DEATH PILE flag that ages every day on its own, with the sold date, price, profit and return on cost read back from Sales
• Sales, one row per sale: the platform fee is worked out from Setup, then payout, cost of goods, profit, margin, return on cost and days to sell
• Expenses, one row per receipt on its Schedule C line, with a mileage log at the IRS standard rate, 72.5 cents through June 2026 and 76 cents from July, both editable. Platform fees and shipping labels are never typed here; they come off each sale
• Platforms, what each one actually took: sales, gross, fees, labels, payout, profit, margin, average sale, effective fee percent and a 1099-K test per platform, plus the same sale priced on every platform side by side
• Quarterly Tax, the four IRS periods with their real due dates: profit, expenses, net, what to set aside, what you paid, what is still owed, and a status that counts the days
• Schedule C, lines 1 to 42 the way the form reads, with a reconciliation that shows why cost of goods sold and your sold-item cost differ
• Dashboard, profit after every fee and expense, sell-through, the death pile, this month, the next quarterly payment, and the money by platform and by category with two charts
• Year View, twelve months of buying, selling, fees, labels, cost of goods and profit

The worked sample inside is a one-person resale shop eight months into 2026: 209 items costed, 165 sold across eBay, Poshmark, Mercari, Depop, Whatnot and local pickup, $14,735.95 of gross sales, $1,963.45 of platform fees, $938.10 of labels, $8,891.86 of profit after the fee, the label and the cost, 80.5 percent sell-through, and nine items that have sat 120 days or more, $137.00 at cost, the oldest a Coach tote bought in December. Clear the sample rows and the formulas stay.

THE NUMBER THIS FILE EXISTS FOR

The same $68.00 item, with $9.50 of shipping charged and an $8.20 label, nets $66.29 on Depop and $54.40 on Poshmark. That is $11.89 on one sale, and it is on the Platforms tab as a table you can price against before you list.

WHO IT IS FOR

Thrift and estate-sale resellers, clothing and shoe flippers, Poshmark and Mercari sellers, eBay stores, Whatnot streamers, and anyone who has a bin of unsold items and no idea what it cost them.

WHAT YOU GET

The workbook in four color editions, Colorful, Light, Dark and Editorial, plus a bundle zip, instant download, and a full narrated video walkthrough on YouTube. Free updates.

HOW IT WORKS

Open in Excel, or upload to Google Sheets, or open in Numbers. Fill in Setup once. Cost every item the day you buy it. Log every sale. Read the Dashboard on Sunday and the Quarterly Tax tab before the fifteenth.

WATCH THE TUTORIAL (every tab, narrated, 7 minutes): https://youtu.be/0K1PjbXv_P0

Digital product, so all sales are final; message me if anything is unclear and I will help.

A record-keeping tool that does the arithmetic on the items, sales and receipts you enter; not tax, legal or accounting advice. The platform fee rates are the published US rates in August 2026 and are yours to update. Hobby-loss rules, inventory accounting elections, the qualified business income deduction and your state's 1099-K threshold are your preparer's call.