Rendered Fits · Original research
Shopify Size Chart Report 2026: what 829 fashion stores tell shoppers about size and fit
We audited the size charts, fit notes and model information of 829 Shopify fashion stores and 107,138 sized products on 24 September 2026. Only 31.6% of stores had a size chart that could be read as text on the page, only 20.3% of sized products said how they fit, and only 10.3% said what size the model wears.
By the Rendered Fits team · Published 29 September 2026 · Data collected 24 September 2026 · Download the figures (CSV)
Key findings
Most size charts are hard for people and machines to read. Of the 829 stores, 27.7% had no size chart our scanner could find, 27.1% published it as a picture, 7.7% loaded it only through a sizing app and 4.8% loaded it after the page. A picture cannot be searched or read aloud without alt text, and it is invisible to search engines and AI assistants that read page text. Many AI crawlers fetch the raw HTML and do not run JavaScript, so charts injected by scripts may be missed too.
Measurements alone do not tell a shopper which size to buy. A chart gives body or garment measurements; a fit note ("true to size", "relaxed fit", "size up if between sizes") tells the shopper how to use them. 78.9% of stores had fit notes on fewer than 30% of their sized products, and 27.6% had none at all.
The model is a missed reference point. "Model is 5'9" and wears a size 10" lets a shopper compare themselves with the photo. 73.8% of stores never gave the model's size or height on any sized product.
Label hygiene is a quieter problem. 23.3% of stores labelled the same size differently across products (for example "S", "Small" and "SM"), which makes filters, charts and size recommendations harder to match. Among stores with a readable chart, 47.7% gave measurements in only one unit.
All figures
| Measure | Result | Share of | Note |
|---|---|---|---|
| Size chart readable as text on the page | 31.6% | Store | No chart problem found by the scanner |
| No size chart found | 27.7% | Store | No chart on product pages, guide pages or descriptions |
| Size chart is an image | 27.1% | Store | Chart published as a picture |
| Size chart loads only through a sizing app | 7.7% | Store | Chart injected by an app script |
| Size chart loads after the page | 4.8% | Store | Guide or button present, no readable chart in the HTML |
| Same size labelled different ways | 23.3% | Store | e.g. "S", "Small" and "SM" across products |
| Sizes sold but missing from the chart | 9.0% | Store | A size on sale that the guide does not cover |
| Readable charts in one unit only (cm or inches) | 47.7% | Store with readable chart | n = 262 |
| Fit notes on fewer than 30% of sized products | 78.9% | Store | "true to size", "relaxed fit", "size up" and similar |
| No fit notes on any sized product | 27.6% | Store | |
| Sized products that say how they fit | 20.3% | Product | Weighted across 107,138 sized products |
| Model's size or height never given | 73.8% | Store | |
| Sized products that give the model's size or height | 10.3% | Product | Weighted across 107,138 sized products |
| Fit notes on 30%+ and model info on 20%+ of products | 7.2% | Store | Both basics covered |
| A sizing app detected | 10.5% | Store | Kiwi Sizing 67 stores, True Fit 10, others 11 |
Store percentages use 829 stores as the base unless stated. Product percentages are weighted by each store's number of sized products.
What fashion merchants can do
- Publish the size chart as text. Use an HTML table on the product page or a linked guide page, with measurements in centimetres and inches. If you keep an image, add the same figures as text.
- Add a fit note to every product. One line is enough: how it fits, and what to do if between sizes. Write it from the garment's actual measurements, not a generic line.
- Give the model's height and size. Add it to the description or a product metafield so it appears on every page.
- Use one label per size. Pick "S" or "Small" and apply it across the catalogue so charts, filters and apps can match sizes.
- Check what a machine sees. Run the free size chart audit on your store and the AI agent fit check to see what an assistant can read.
Rendered Fits is a Shopify app that turns your size chart and fit notes into a size recommendation for each product, sizes whole outfits with Complete the Look and adds virtual try-on previews. The Free plan covers one product; Complete is $349 per month with a 14-day trial.
Method and limits
Sample. 1,186 Shopify fashion store domains from the Rendered Fits research list of independent fashion brands. 903 had a readable public product feed and 829 sold products with clothing size options; those 829 are the base. The list was built for our own market research, so it is not a random sample of all Shopify stores. Store names are not published.
Collection. On 24 September 2026 we ran the Rendered Fits size chart audit on each store. It reads the store's public /products.json feed (up to 250 of the most recent products) and product pages and size guide pages linked from them. It does not run JavaScript, log in or place orders.
Checks. "Readable as text" means the scanner found a chart as text or an HTML table and none of these problems: no chart found, chart as an image (an image whose file name or alt text names a size chart or guide), chart loaded only by a known sizing app, chart loaded after the page, or chart not checked. A fit note is text matching phrases such as "true to size", "runs small", "size up", "relaxed fit" or "between sizes". Model information is text such as "model is 5'9"" or "wears a size 10". Sizing apps are detected by their scripts on product pages.
Limits. The scanner reads page HTML, so a chart shown only after a click or by a script it does not recognise may be counted as missing; it measures what a crawler can read, which is also what many AI assistants can read. Pattern matching can miss unusual wording. Results describe one day and change as stores update. This is descriptive data, not evidence that any of these gaps causes returns or lost sales.
Cite this report: Rendered Fits (2026). Shopify Size Chart Report 2026: what 829 fashion stores tell shoppers about size and fit. https://www.renderedfits.com/size-chart-report-2026/ (CC BY 4.0)
Questions
How many Shopify fashion stores have a readable size chart?
In our audit of 829 Shopify fashion stores on 24 September 2026, 31.6% had a size chart that our scanner could read as text on the page. 27.7% had no size chart we could find, 27.1% published the chart as an image, 7.7% loaded it only through a sizing app and 4.8% loaded it after the page.
Why does it matter if a size chart is an image?
An image cannot be read by screen readers without alt text, cannot be searched on the page, and cannot be read by search engines or AI assistants that read page text. Many AI crawlers fetch the raw HTML and do not run JavaScript, so a chart that is a picture or is injected by a script may be invisible to them.
What are fit notes?
Short statements on a product page that say how a garment fits, such as "true to size", "relaxed fit" or "size down if between sizes". A size chart gives measurements; a fit note tells the shopper which size to choose. Only 20.3% of the sized products we scanned had one.
How was the audit done?
We ran the public Rendered Fits size chart audit on each store's public Shopify product feed (up to 250 of its most recent products) and on product pages and size guide pages linked from them. The method section on this page lists every check.
Can I check my own store?
Yes. The free size chart audit at renderedfits.com/size-chart-audit runs the same checks on any Shopify store with a public storefront. No sign-up is needed.
Can I use these figures?
Yes, under CC BY 4.0. Please cite "Rendered Fits, Shopify Size Chart Report 2026" and link to this page. The CSV of all figures is linked below.