Size Run
Reseller profit tracker: see which platform actually pays
Fees, net profit, margin and ROI per platform and month.
Most size splits start as a gut feeling or a generic industry ratio. This free workbook builds the curve from your own sales history instead, and then turns it into units per size for the styles you are about to buy.
What is a size curve?
A size curve is the share of a buy that each size should get. If, say, a size M made up a quarter of last season's net sales, it earns about a quarter of the next buy, adjusted for what you know has changed. Buying by curve instead of buying "one of each" reduces the stock that is left over in the sizes nobody wanted while the popular sizes sell out.
How the Starter calculates it
- Input per size: units sold, units returned and weeks in stock. Sizes can be letters (XS to XXL) or numbers.
- Sell-out correction: a size that was out of stock for part of the season is scaled up to a full-season selling rate, so the curve does not punish sizes that simply ran out.
- Returns netted out: the curve uses net units and shows the return rate for each size.
- Buy plan: enter the total units for a style and the Starter splits it by size, rounded to your pack multiple.
- Low-history warning: if a curve rests on fewer than 30 net units, the workbook tells you it is only a rough guide.
What you get
One workbook with four tabs (Instructions, Inputs, Curves, Buy_Plan), a one-page Quick Start PDF and labelled example data for a tops curve from XS to XXL. Yellow cells are for your input, green cells are formulas. It is a standard .xlsx file with no macros and built for Excel and Google Sheets, checked in LibreOffice.
Limits of the free version
The free Starter handles one curve, up to six sizes and up to five styles. If you need more, the Size-Curve Planner inside the Buying & Wholesale Kit covers three curves, eight sizes and 20 styles. The Starter is a planning aid: it does the arithmetic on your history, it does not forecast demand, and a new style without comparable history still needs your judgement.
Who it is for
Small apparel brands planning a production run, boutique buyers placing size-level orders, and merchandising students who want to see the mechanics of a size curve in a file they can inspect cell by cell.
Get the free Size-Curve Starter Full Buying & Wholesale Kit on Etsy Line Sheet template on Etsy Free. Gumroad asks for an email address only to deliver the file.
Frequently asked questions
Do I need sales history?
Best results come from your own units by size. With no history, use your best estimate or a comparable product you have sold; the low-history warning shows when the result is only a rough guide.
Does it work in Google Sheets?
Built for Google Sheets: upload the .xlsx to Google Drive and open it with Sheets; formulas are standard.
Letter or numeric sizes?
Both. Size labels are free text.
Is it really free?
Yes. The price on Gumroad is $0.
