How to build a reseller inventory spreadsheet that still works at 2,000 items

Most resellers start with a list of what they bought. It breaks when items are cross-listed, stored in different totes, returned or sold months later. This guide shows a structure that holds up: where each item is, what it cost, where it sold, and what you actually kept after fees. You can build it yourself in 30 minutes, or download the free template with the formulas already in place.

1. Give every storage spot a code

A bin is anything you can walk back to: a tote, a shelf slot, a section of a clothing rail. Name them with short codes: A01, A02… or R2-S1-B4 (rack 2, shelf 1, bin 4). Write them in a Bins tab with a note of where each one is.

Label the bins. A printed QR code containing the bin code lets anyone confirm the right bin with a phone camera. You can make a whole sheet of them free with the bulk QR generator (paste a list, choose an Avery 5160 or A4 layout) — see Avery label templates.

2. One row per item, with a SKU that starts with its bin

Use a format like A01-0007: the bin, then a running number that never repeats. Put the same SKU in the listing's SKU or custom-label field on eBay, Poshmark or Mercari, so the sale notification tells you which bin to open.

SKU | Item | Bin | Source | Bought | Cost | Status | Listed on | List date | List price | Sold on | Sold date | Sale price | Shipping charged | Sales tax | Label cost | Fees | Net profit | ROI | Days to sell

Make Status a dropdown (Unlisted, Listed, Sold, Returned, Donated/Kept) so filters and totals stay reliable. If an item moves, change its Bin column; the SKU can stay.

3. Put platform fees in a table, not in your head

Create a Settings tab with one row per platform: fee %, whether the % also applies to shipping, any fixed per-order fee and any flat-fee rule. Then each sale looks up its platform. A simplified version of the rule used in our template:

Fee = IF(price < flat_threshold, flat_fee,
        pct × (price + IF(pct_on_shipping, shipping, 0) + IF(pct_on_tax, sales_tax, 0))
        + fixed_fee
        + processing_pct × (price + shipping) + processing_fixed)

Typical US defaults (verify — they change): eBay 13.6% of item + shipping + tax plus $0.30–$0.40; Poshmark $2.95 under $15, otherwise 20%; Mercari 10% of item + shipping; Depop 3.3% + $0.45 processing; Whatnot 8% + 2.9% + $0.30. Try them on one sale with the reseller fee calculator.

4. Profit, ROI and days to sell

Net profit  = sale price + shipping charged − label cost − fees − item cost
ROI         = net profit ÷ item cost
Days to sell = sold date − list date

Sum net profit by sold month for a simple P&L, and subtract supplies, storage and mileage from a separate Expenses tab.

5. Review aging stock every week

Add a "days listed" column for unsold items (TODAY() − list date) and colour anything over 90 days. Count items in 0–30, 31–90, 91–180 and 180+ day buckets. The older buckets are where your cash is stuck: drop the price, relist, bundle, or move it to another platform.

Free template

Questions