Home › Resources › Open data

Clothing size and fit statistics 2026: our original data

For 80% of 1,383 UK and US Shopify clothing stores, the product we sampled reached AI shopping assistants with no size chart, and only 31.6% of 829 fashion stores show a size chart that can be read as text. This page collects every sizing statistic from our own research in one place. Each figure gives its sample, its date and a DOI, so it can be quoted and checked.

By Sienna Stones · Published 13 November 2026 · Figures from studies run 24 September to 12 November 2026

What AI shopping assistants receive

80% of 1,383 UK and US Shopify clothing stores: the product we sampled reached AI shopping assistants with no size chart and no measurements.
4% of those stores (59 of 1,383): the sampled product carried a full size chart.
13 of 14 letter-size answers ChatGPT gave were Medium when it had no readable size chart, in a small test of 2 October 2026.
14 of 15 products where ChatGPT matched the brand's own size chart, when the chart was readable (same test).

Source: AI sizing study 2026, one product from each of 1,383 UK and US Shopify clothing stores, looked up in Shopify Catalog on 21 and 22 October 2026. doi:10.5281/zenodo.24165873

How fashion stores publish size charts

31.6% of 829 Shopify fashion stores had a size chart that could be read as text on the page.
27.1% of those stores published their size chart as an image, and 27.7% had no size chart the scanner could find.
20.3% of 107,138 sized products said how they fit, such as "true to size" or "size up".
10.3% of sized products gave the model's size or height; 73.8% of stores never did on any sized product.
23.3% of stores labelled the same size in different ways across products, such as "S", "Small" and "SM".
47.7% of stores with a readable size chart gave measurements in one unit only (n = 262).

Source: Shopify Size Chart Report 2026, 829 Shopify fashion stores and 107,138 sized products, scanned 24 September 2026. doi:10.5281/zenodo.24165866

What product descriptions say about size

70% of sized product descriptions on the average store gave no measurement, no sizing advice and no model size (459 Shopify fashion stores).
12% of sized product descriptions gave a garment measurement, and 9.7% gave sizing advice.
16% of dress descriptions gave a garment measurement (27,216 dresses).
3.3% of shoe descriptions gave a measurement (2,083 shoes).

Source: Sizing information by category, 459 Shopify fashion stores and 74,111 sized products, read from public product feeds on 21 October 2026. doi:10.5281/zenodo.24165871

What a UK size 12 measures

92 to 97 cm is the bust of a UK women's size 12 across 26 retailers that publish one figure per size; the middle value is 94 cm.
74 to 80 cm is the size 12 waist across the same retailers; the middle value is 76 cm.
99 to 108 cm is the size 12 hip measurement, a 9 cm spread, close to two sizes at most retailers; the middle value is 102 cm.
Size 10 = size 12 Oliver Bonas publishes 92, 75 and 100 cm (bust, waist, hips) for a size 10; Marks & Spencer publishes the same figures for a size 12.

Source: UK size 12 measurements, size charts published by 27 UK fashion retailers, read 12 November 2026. doi:10.5281/zenodo.24165875

How to quote these figures

Name the study, its sample and its date, and link to the source page or the DOI. For example:

"For 80% of 1,383 UK and US Shopify clothing stores, the sampled product reached AI shopping assistants with no size chart or measurements." Rendered Fits, AI sizing study 2026 (1,383 stores, October 2026), doi:10.5281/zenodo.24165873

All four studies are on our open data page, in a machine-readable catalogue, and archived on Zenodo with a DOI. Every statistic on this page is also in statistics.md. Journalists who want a comment, the underlying numbers or a chart can reach us through the about page.

Each figure describes its own sample. The studies used different stores, dates and methods, so the percentages should not be added together or set against each other as if they measured the same thing.

Questions

Do AI shopping assistants see a store's size chart?

Often not. In our AI sizing study of 1,383 UK and US Shopify clothing stores (21 to 22 October 2026), 80% of the sampled products reached AI shopping assistants through Shopify Catalog with no size chart and no measurements, and only 4% carried a full size chart. Charts shown as images, drawn by a size chart app or kept on a separate page did not travel with the product.

How many fashion stores have a readable size chart?

In our scan of 829 Shopify fashion stores on 24 September 2026, 31.6% had a size chart that could be read as text on the page. 27.1% published it as an image and 27.7% had no chart our scanner could find.

How often do product pages say how clothes fit?

Rarely. 20.3% of 107,138 sized products in our September 2026 scan said how they fit, and 10.3% gave the model's size or height. In a separate October 2026 read of 74,111 product descriptions, 70% on the average store gave no measurement, no sizing advice and no model size.

What are the measurements of a UK size 12?

Across 26 UK retailers' own size charts read on 12 November 2026, a women's size 12 was a bust of 92 to 97 cm, a waist of 74 to 80 cm and hips of 99 to 108 cm. The middle values were 94, 76 and 102 cm.

Can I use these statistics?

Yes. Our own figures are free to reuse under CC BY 4.0 with credit to Rendered Fits and a link to the source page or its DOI. Retailer size charts belong to the retailers; we publish our ranges and middle values, not their charts as a dataset.

About Rendered Fits. Rendered Fits is a Shopify app for fashion brands that recommends a size for supported products from the brand's own size chart, and can show shoppers an optional AI try-on preview. There is a Free plan (one product, 5 try-ons a month, with a PREVIEW watermark). Complete is $349 a month plus any applicable taxes, with a 14-day trial of 50 try-ons in total, then 1,000 try-ons per paid cycle. Extra try-ons cost $0.50 each, but only if you turn them on and set a spending cap. Enterprise is $999 a month plus any applicable taxes, with 5,000 try-ons per paid cycle, then $0.35 each extra on the same terms, and no trial.