Selling on Several Platforms: Keeping Size Data Consistent
By the ZeDaq.ai team · · 4 min read
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When selling on several platforms, keep size data consistent by holding one master size chart, use the same size labels and measurement units everywhere, and update every platform from that single source. When each store or marketplace has its own copy, the copies drift apart and shoppers see different advice for the same garment.
This guide is for store owners and developers who sell on more than one site, such as a WooCommerce shop plus a Wix or custom storefront. If you add try-on or size recommendations, a virtual try-on setup for WooCommerce will only be as accurate as the chart behind it.
Why does size data drift between platforms?
Drift happens because each platform stores sizes in its own way, and people update them one at a time. Typical causes include:
- A chart is corrected on one site and forgotten on another.
- One platform uses inches while another uses centimeters.
- Labels differ, such as "M" on one site and "Medium" or "UK 12" on another.
- A product is renamed or restocked with a new fit, but old charts stay online.
Shoppers notice. If your site says a dress fits a 36-inch bust in one place and a 38-inch bust in another, they stop trusting both.
What goes into a master size chart?
Create one spreadsheet or file that is the only place you edit sizes. For each garment type, list:
| Field | Example entry |
|---|---|
| Garment type | Tops |
| Size label | M |
| Measurement | Chest |
| Minimum | Your figure |
| Maximum | Your figure |
| Unit | Centimeters |
| Fit note | Runs small, size up if between sizes |
This is a template, so use your own measurements. Use body measurements, not the flat width of the garment, and keep one chart per garment type because tops, outerwear, dresses and bottoms fit differently.
How do you choose one set of labels and units?
Decide once, and write it down.
- Choose a single unit for the master chart. Convert for display on other sites if needed.
- Pick one label style per market, such as letters or numbers, and keep it.
- Decide how to show regional sizes, for example a conversion row on each product page.
- Name garment types the same way everywhere, so "bottoms" never becomes "trousers" on one site and "pants" on another.
If you sell in several countries, note which standard each regional label follows and say where it comes from. When in doubt, show the brand's own chart.
How do you update every platform from the master chart?
Which approach fits a small catalog?
For a small catalog, update each platform by hand from the master file, then record the date. Use a checklist so no site is skipped.
Which approach fits a larger catalog?
A larger catalog benefits from a product data feed or a script that pushes sizes to each channel. Developers can use product attributes and structured data so the same values appear in the page and in search. The guide to structured data for clothing products shows how to mark up size, color and material.
Swatches also need care. See WooCommerce product swatches for color and size to keep the displayed options matching your data.
How do sizing tools fit into this?
A sizing tool reads your chart, so a wrong chart gives wrong advice. With ZeDaq.ai, merchants enter their own size guide in Dashboard → Size charts, or in the Shopify app, with one chart per garment type. The scan recommends the store's own labels and sizes up to the largest relevant measurement.
For non-Shopify stores, the script-tag widget adds "Try it on" and "Find my size" to the product template. The widget key must be locked to the store's domain. Developers who want a custom flow can call the REST API, as covered in the guide to the try-on API for ecommerce developers.
Since a chart is entered per store, keep your master chart open when you update it so the values match what you publish elsewhere.
How do you check that everything still matches?
Run a short audit every time you launch a collection:
- Pick five products and compare their size information on every channel.
- Test a size recommendation on each site with the same body measurements.
- Compare labels, units and fit notes line by line.
- Fix differences at the master chart first, then republish.
Keep a change log with the date, what changed and who changed it. If a customer complains about a mismatch, you can trace it quickly.
Connect sizing and try-on to your store
FAQs
Should I use the same size labels on every platform?
Use the same labels where you can. If a marketplace forces its own format, map your labels to it and keep the master chart as the reference.
What if a platform only allows inches or only centimeters?
Convert from the master chart and round consistently. Do not edit the converted value on that platform alone.
How often should I review my size data?
Review it at each new collection and whenever a supplier changes a pattern. Also check it after returns show a repeated fit complaint.
Does a size chart need to be the same for all products?
No. Use one chart per garment type, and add separate charts when fit differs, such as a relaxed hoodie versus a fitted shirt.
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