Why your size changes from brand to brand

If you have ever been a 6 in one store and a 10 in the next, the problem is not you. In the United States there is no mandatory standard for women’s clothing sizes. Each brand sets its own measurements for each size, and those measurements have drifted over the decades. This guide explains how that happened and how to shop around it.

A short history of US sizing

Wikipedia’s article on US standard clothing sizes sets out the main steps:

With no binding standard, sizes have since moved substantially away from the original tables, a drift often called vanity sizing: the same number label tends to be given to larger measurements over time. Wikipedia describes most modern North American sizes as following looser “catalog sizes” rather than any formal standard.

How much can a “size 8” vary?

The tables reproduced in the Wikipedia article show how wide the range is. Depending on which table you read, a size 8 bust runs from 32.5 inches in an older standard table to 44 inches in a catalog-size table. The same label covers very different bodies.

Comparing two published brand charts

Here is how two established US retailers define their misses sizes, using the measurements published on their own size-chart pages (bust, waist and hip in inches). Talbots’ chart is proportioned for women 5′4″ to 5′8″. L.L.Bean gives bust ranges for its alpha top sizes and single waist and hip values for numbered bottoms.

The two charts are close but not identical. At size 8, for instance, the Talbots waist is 29 inches and the L.L.Bean waist is 28½ inches, with a half-inch difference at the hip as well. On a fitted waistband, half an inch is the difference between comfortable and not. Across all brands, the spread can be far larger.

Letter sizes add another layer

Letter sizes group number sizes, and brands group them differently. Talbots’ chart maps S to sizes 4–6, M to 8–10 and L to 12–14, while L.L.Bean’s chart describes its Small as covering sizes 6–8. So a “medium” at one brand can start a full size away from a “medium” at another.

How to shop around it

1. Measure yourself. Use a soft tape measure for bust (fullest part), natural waist and hip (fullest part). Write the numbers down and check them every so often.
2. Use the brand’s chart, every time. Compare your numbers with the chart on the brand’s own site, not with your usual size.
3. Fit to the hardest measurement. For dresses and tops, the bust often decides; for trousers and skirts, the waist or hip. A tailor can usually take in more easily than let out.
4. Check the height range. Charts like Talbots’ are proportioned for a height band; petite and tall ranges change the lengths.
5. Read garment measurements on resale listings. When buying secondhand, ask for flat measurements rather than trusting the label; see the resale guide.