What is vanity sizing? A size 8 bust grew 5.25 inches between the 1958 and 2011 standards

Vanity sizing is the long-running drift of ready-to-wear clothing toward bigger measurements under the same size label. A women's size 8 is the clearest example. In the U.S. government's 1958 sizing standard it had a 31-inch bust. In the 2011 revision of the ASTM standard that industry now cites, a size 8 has a 36.25-inch bust. That is 5.25 inches more cloth for the same number on the tag, and the standards themselves are the evidence.

The numbers, standard by standard

The table below is built from the misses' size charts reproduced on Wikipedia's vanity sizing page, which cites each standard. We compare the size 8 bust because it appears in every edition.

• Commercial Standard CS 215-58 (1958): bust 31 inches
• Product Standard PS 42-70 (1970): bust 32.5 inches
• ASTM D5585-95 (1995, revised 2001): bust 35 inches
• ASTM D5585-11e1 (2011): bust 36.25 inches

Two cautions. The charts did not all describe the same body: the 1995 table is for women 5 feet 3.5 inches to 5 feet 8 inches tall and the 2011 table is built on a 5 foot 5.5 inch figure, so part of the change is a taller reference woman, not a bigger label. And the same Wikipedia page cites a Sears catalog comparison, reporting that a size 14 dress with a 32-inch bust in 1937 was a size 8 in 1967 and a size 0 in 2011. Whatever the cause, the label and the garment have drifted apart.

Where sizes came from

Before mass production, clothes were made to measure. Ready-to-wear began with men's military uniforms in the 1800s, where a chest measurement was enough. Women's clothing did not fit that logic, and returns of ill-fitting garments were high enough, according to Seamwork's history of the subject, that manufacturers pushed for a standard.

In 1939 the U.S. Department of Agriculture launched a study titled Women's Measurements for Garment and Pattern Construction, measuring 14,698 women across seven states on weight and 58 body measurements. Seamwork notes the sample was skewed, because the criteria required participants to be white and measurements from non-white women who were collected were later excluded. The National Bureau of Standards, now NIST, used that data to publish voluntary Commercial Standard CS 215-58 in 1958. It was updated in December 1970 and then withdrawn in 1983.

What happened after 1983

"Voluntary" is the key word. With no mandatory standard and the government's version withdrawn, each brand set its own size charts. The Wikipedia entry notes that although ASTM standards exist, most companies no longer use them. Seamwork's account is that retailers learned smaller numbers sold, and that the numbers kept sliding.

Not everyone has drifted. Deborah Kreiling, design development director for Simplicity Patterns, told Seamwork that "Our patterns size standard measurements have been the same since the mid-1960s." That gives sewers a fixed reference while store-bought sizes moved. It also means a pattern size and a store size can be several numbers apart for the same person.

Men's sizing drifts too

Vanity sizing is usually discussed for women's clothes, but Wikipedia, citing Esquire, reports that in 2010 pairs of dress pants labeled with a 36-inch waist measured 37 to 41 inches at different U.S. retailers. It also reports a 2011 U.K. study that found misleading labels on more than half of the items checked, with the worst offenders understating waist circumference by 1.5 to 2 inches, and a Mintel finding that the number of men reporting varying waistlines from store to store doubled between 2005 and 2011. These are secondary reports of studies we did not open, so treat them as indicative.

What the current standard actually is

ASTM D5585-21, the Standard Tables of Body Measurements for Adult Female Misses Figure Type, Size Range 00 to 20, was last updated February 17, 2021 and was priced at $72.00 on ASTM's site when we checked on October 21, 2026. It states its purpose plainly: "The use of the body measurement information in Table 1 and Table 2 will assist manufacturers in developing patterns and garments that are consistent with the current anthropometric characteristics of the population of interest." It adds that this "should in turn reduce or minimize consumer confusion and dissatisfaction related to apparel sizing."

Note what ASTM does not say. Its scope section says the tables are body measurements that can serve as a baseline for designing apparel. It is not a rule and nothing obliges a brand to follow it. It includes two shape types, curvy and straight, on certain measures. We did not purchase the full tables, so the numbers above come from the Wikipedia reproduction of earlier editions.

Why it matters when you shop

A size number is a brand's decision, not a measurement. Two garments labeled 8 can differ by inches. The practical response is boring and reliable: read the garment measurements when a retailer lists them, compare them to a piece that fits you, and treat the tag as a starting guess. Many brands publish size charts, and a chart with flat measurements in inches or centimeters is worth more than the label.

For brands, the consequence is returns, a cost Seamwork traces to the years after World War I. A tag that does not predict the garment is a fit problem and a data problem, and fixing it means publishing measurements, not just numbers.

Our take

Vanity sizing is real in the sense that the labels moved while the standards stayed on paper, and we can show the movement in a published table. What nobody can show is a single cause. A taller reference figure, a changing population and a marketing incentive all fit the data. The sound consumer rule is to ignore the number and shop by the measurements.