Most women wear shoes that are the wrong size for their feet, a study has found.

Most participants in a new Australian study wore shoes that did not correspond to the size calculated based on their actual foot length. This discrepancy was found in 72% of women using the American sizing system and 65% using the European system. Moreover, women more often chose shoes larger than predicted based on foot length alone. The study by RMIT University researchers was published in the International Journal of Fashion Design, Technology and Education. [1]

The authors believe the reason may not be that women "don't know their size." Modern mass-produced shoes are classified primarily by length, whereas two feet of the same length can vary greatly in forefoot width and circumference. In a new study, women who were the same foot size had forefoot circumferences that varied by a maximum of 40 millimeters in the American sizing system and 37 millimeters in the European system. [2]

As a result, a shopper may be forced to choose a shoe size larger simply because the appropriate shoe length is too narrow. In the American system, 59% of participants wore a size larger than their calculated length, while in the European system, the figure was 52%. Researchers believe this "sizing up" is a possible way to compensate for shoe width. [3]

The study has implications beyond the fashion industry. Previous studies have linked poorly fitting shoes to foot pain, calluses, corns, and some toe deformities. However, the new publication does not, by itself, prove that sizing discrepancies caused foot problems in the women studied: the participants were healthy, and the primary objective was to study anthropometry and sizing. [4]

Key findings of the study

Indicator	Result
Participants	107 women
Age	18-54 years old
US size discrepancy	72%
EU size discrepancy	65%
Wore a larger US size	59%
Wore a larger EU size	52%
Maximum difference in foot circumference within one US size	40 mm
Within one EU size	37 mm
Have you had at least one recurring problem with shoe fit?	68%
To cover the detected width range	approximately 6-7 fullness options
DOI	10.1080/17543266.2026.2709095

[5]

How the study was conducted

The study included 107 healthy women aged 18 to 54 years living in the Melbourne metropolitan area. Participants were recruited using purposive and convenience sampling. Women with known medical conditions that could significantly affect foot morphology were excluded. [6]

The authors consciously sought to obtain an ethnically diverse group. Participants represented ten origin categories, including Northeast and Southeast Asia, South Asia, Northwest Europe, Southern and Eastern Europe, Australia, New Zealand, Africa, the Americas, North Africa, and the Middle East. Twenty-four women reported origins from two or more groups. [7]

First, the women answered questions about their typical shoe size and any problems they encountered when trying on shoes. The researchers deliberately administered the survey before measuring their feet to ensure that knowing their actual sizes wouldn't cause the participants to adjust their answers retroactively. [8]

Both feet were then measured using a modified Brannock device—a tool commonly used in shoe stores—and a measuring tape. The women stood with their weight evenly distributed. The larger of the two feet was used for further sizing; this approach follows the common principle of fitting shoes to the larger foot. [9]

American, British, and European sizes were then determined using the international ISO size conversion standard and compared with the women's self-reported sizes. Thus, the study compared not just a box label with another label, but self-reported sizes with anthropometric foot measurements. [10]

What exactly was measured?

Indicator	What characterizes
Foot length	Total foot length
Arch length	Length from heel to metatarsal joint area
Joint width	Forefoot width
Joint girth	Forefoot circumference
Both feet	Allowed to take into account natural asymmetry
Self-assessed size	The size a woman usually buys

[11]

The main problem turned out to be not the length, but the three-dimensional shape of the foot.

Most conventional sizing systems create the impression that foot size is a practically one-dimensional quantity. A person measures the length of their foot, gets a number like EU 38, and expects all shoes marked 38 to fit. In reality, shoes are three-dimensional objects, and feet vary not only in length but also in width, volume, arch height, and toe shape.

This is precisely what a new study demonstrated. Even among women with the same foot length, the variation in joint girth—the circumference of the metatarsophalangeal joint area—reached 40 millimeters for American sizes and 37 millimeters for European sizes. For a shoe last, such a difference is extremely large. [12]

In the standard American system, the transition between fullness variations corresponds to a change in girth of approximately 6.35 millimeters. Therefore, according to the authors' calculations, to cover the entire detected range within certain sizes, approximately six fullness variations would theoretically be required. For the European system, the requirement could reach approximately seven. [13]

In a physical store, however, most styles are sold in only one width. Shoppers are presented with a variety of length options—37, 38, 39, and so on—but often have little choice but to choose the same length in a different width. Therefore, a woman with short but wide feet is faced with a choice: either a shoe of the correct length with excessive pressure on the sides, or a longer model that at least provides sufficient width.

The authors believe that this circumstance provides a more plausible explanation for the widespread choice of larger sizes than the assumption that women simply make mistakes when buying shoes. A single size does not adequately describe the three-dimensional shape of the foot. [14]

Why one size number is not enough

Foot characteristics	Is it considered a normal size?
Length	Yes, mainly
Width	Limited
Front circumference	Often hardly reflected at all
Lifting height	Usually no
Finger shape	No
Asymmetry of the right and left feet	No
Ethnic morphological differences	Usually not specifically taken into account

72% of participants wore the "wrong" US size - but this isn't necessarily a mistake.

Using the American system, 72% of women's usual shoe sizes did not match the size calculated by researchers based on their foot length. Using the European system, the discrepancy was 65%. At first glance, the results appear to suggest that most women systematically make mistakes when choosing shoes. [15]

But the direction of this error was particularly telling. Under the American system, 59% of all participants chose shoes larger than their foot length suggested. Under the European system, 52% did so. That is, the main tendency was not to wear shoes that were too tight, but rather to wear larger lengths. [16]

Researchers suggest that the increase in length may be a price paid for the extra width and volume. When a shoe last is typically scaled up, other dimensions also increase along with the length. Therefore, going from a 38 to a 39 size often adds a few millimeters to the forefoot—even if the extra length is completely unnecessary.

But this solution isn't perfect either. Shoes that are too long can compromise heel support and alter the position of the foot within the shoe. So, a person might gain sufficient forefoot width but still experience heel slippage or other fit issues.

Thus, the title of the article, “One size fits small,” reflects the central paradox of the study: one linear number may be too poor a description of the actual geometry of the human foot.[17]

What happened to the size?

Observation	US	EU
The usual size was different from the calculated one	72%	65%
We chose a size larger than calculated.	59%	52%
The authors' main hypothesis	Lack of width forces the size to be increased	Same
Alternative explanations	Differences between brands, personal preferences, and model features	Same

[18]

The sizes of two feet of the same person also often differ.

The natural asymmetry of the human body creates an additional problem. Ninety-three of the 107 participants had different lengths of their left and right feet. The differences were small, but common enough to not be considered rare. [19]

The average difference between the left and right feet was approximately 2.6 millimeters in length, 3.8 millimeters in arch length, 1.7 millimeters in width, and 6.3 millimeters in forefoot circumference. One foot could be longer and the other wider, further complicating the difficulty of matching the geometry to a single size.[20]

Interestingly, there was no significant difference in frequency between the right and left sides: some participants had a larger right foot, while others had a larger left foot. This is consistent with previous anthropometric studies and shoe selection practices.

That's why professional advice typically recommends fitting closed-toe shoes to larger feet. In the current study, researchers used the same principle: choosing the longer or wider of the two feet for classification.

However, even this approach doesn't completely solve the problem. If one foot is noticeably smaller than the other, shoes that are optimal for the larger foot may not hold the smaller foot well. For some people, this difference must be compensated for with an insole, lacing, or other means of adjusting the fit.

Asymmetry of the participants' feet

Measurement	Average difference between feet
Length	2.6 mm
Length of the arch	3.8 mm
Front width	1.7 mm
Front circumference	6.3 mm
Participants with different foot lengths	93 of 107

[21]

68% of women regularly experienced shoe fit issues.

The discrepancy between anthropometric and habitual shoe sizes turned out to be more than just a mathematical quirk. Sixty-eight percent of participants reported at least one recurring problem with shoe fit when purchasing shoes. Only 34 of the 107 women reported no such problems. [22]

One of the most common complaints was insufficient width: 25 women reported that their shoes were often too narrow. However, the problem also worked the other way around: 21 participants experienced shoes that were too wide. This further confirms that the "average" last may not fit the entire population well.

Another 25 women cited sizing inconsistencies—for example, the same size across different manufacturers or even different models within the same brand felt completely different. Other complaints included discomfort, foot shape issues, heel slippage, lack of available sizes or half sizes, and length inconsistencies.

This diversity explains why the simple advice "measure your foot and buy the right size" doesn't always work. Even if a person knows their foot length in millimeters, they still don't know how wide a particular shoe is on the inside, how much volume it has in the toe box, or what shape the manufacturer used to create the last.

Researchers believe that more information needs to be provided to consumers directly at the point of sale – not just the conventional EU 39 or US 8, but also information about the actual length, width and fit features of a particular model. [23]

The most common problems

Problem	Participants
No recurring issues reported	34
The shoes are too narrow	25
Inconsistent sizing across different models/brands	25
The shoes are too wide	21
General problem of comfort	13
The shoes are too big	7
Morphological features of the foot	6
Features of specific styles	6
The heel slips out	5
The shoes are too small	4
Other specific issues	We met less often

One woman could have multiple problems, so the categories should not add up to 107. [24]

Why Shoes That Are Too Tight Are More Than Just a Matter of Comfort

Shoe fit is important because constant pressure and friction affect the skin, toes, and forefoot. A previously published literature review found that 63 to 72% of participants in various studies wore shoes that were inappropriate for the length or width of their feet. Poor fit was associated with pain, calluses, corns, and deformities of the lesser toes. [25]

Insufficient toe width is particularly problematic. In some studies of women, shoes were significantly more likely to be narrower than the actual foot. A systematic literature search also found a link between insufficient width and calluses, corns, certain toe deformities, and pain. [26]

However, causality must be interpreted with caution. For example, a person with a pre-existing hallux valgus may choose larger shoe sizes or experience more problems with fit. Therefore, the observed association between footwear and the condition does not always allow one to determine which developed first.

For people with diabetes, the issue takes on additional significance. Impaired foot sensation can make it difficult to notice pressure or rubbing, and skin damage can develop into ulcers. A literature review linked improper shoe length to ulcers in some diabetic patient groups. [27]

However, the new RMIT study was not conducted in people with diabetic feet and did not examine the incidence of the condition. Therefore, its medical significance lies primarily in demonstrating a structural cause of possible poor fit: mass-produced footwear may not adequately address the diversity of human feet. [28]

What is known about poorly fitted shoes?

Possible problem	What does the previous literature show?
Pain in the feet	The association has been found repeatedly
Corns and calluses	Associated with inappropriate width and pressure
Deformations of the small fingers	A connection was discovered
Hallux valgus	There are observational links with insufficient width
Diabetic ulcers	Poor fit is especially important in high-risk groups
Has new RMIT study proven causation?	No

[29]

Why half sizes don't solve the problem

At first glance, increasing the number of half sizes seems like a logical solution. If a shoe between a 38 and 39 fits uncomfortably, you can add a 38.5. However, the authors show that this primarily addresses the length issue, while the main variation may lie elsewhere. [30]

If a person needs a size 38 in length but much more room in the forefoot, a 38.5 or 39 may indeed feel subjectively more comfortable. However, this increases not only the width but also the length of the last. As a result, the shoe becomes roomier in the wrong places.

A much more straightforward solution would be to sell one size in several widths: for example, 38 narrow, 38 regular, 38 wide, and so on. In the study, the range of circumferences was so wide that it would take approximately six American or seven European widths to cover the full range within individual sizes. [31]

The authors don't claim that every store is required to immediately stock seven widths of each model. Such a system would significantly complicate production, logistics, and inventory. However, the data obtained demonstrates the extreme simplification that occurs when the market offers virtually the entire range of foot sizes in just one width.

According to co-author Saniyat Islam, expanding width options would potentially improve fit more than continuing to focus solely on length and half sizes.[32]

Two ways to increase your product range

Solution	What changes
Half size	First of all, the length
Larger size	Length + partially width and volume
Separate completeness	Width/volume without the need to dramatically increase the length
Several shoe trees	Allows you to take into account different foot shapes
Actual dimensions in millimeters	Makes it easier to compare brands

Ethnic diversity may be another missing factor in shoe design.

Australia is particularly interesting for such research due to its ethnic diversity. The authors note that approximately 30% of the country's residents were born outside its borders, while traditional shoe design systems have historically been formed primarily based on limited Western anthropometric data. [33]

In the new sample, foot morphology showed a wider range than in a number of studies of homogeneous populations in Japan, Taiwan, Hong Kong, or Bangladesh. In some respects, the results were closer to studies in Malaysia, another country with a distinctly multiethnic population. [34]

An interesting pattern emerged among the 25 participants who reported that shoes were often too tight. About 60% of them were of Northeast, Southeast, or South Asian descent.[35]

However, the researchers specifically caution that the sample size was too small to demonstrate differences between ethnic groups. It's impossible to conclude from 25 cases that a particular ethnic group necessarily has wider feet or requires a different shoe size.

The significance of the result is rather conceptual: if companies sell products to a multi-ethnic society, it is wise to test their lasts on a sufficiently diverse anthropometric sample, rather than assuming that one historical "average foot" represents all buyers.[36]

What the ethnic analysis showed

Result	Interpretation
25 women complained about shoes that were too tight.	A common sampling problem
60% of these 25 had origins from three Asian macrogroups	Interesting signal
Is this enough to compare ethnic groups?	No
What is needed	Larger studies
Practical conclusion	Footwear design should take into account the diversity of foot morphology

[37]

Another problem is that size 38 can mean different lengths in different brands.

Researchers analyzed shoe size charts available on the Australian market and discovered significant differences in the lengths corresponding to the same European size. This illustrates a fundamental problem in the modern footwear market: international sizes appear standardized, but the actual last of a particular manufacturer can vary.

European, American, and British sizing systems use different historical principles. Some Asian systems and Mondopoint are much closer to the actual foot length in millimeters, while EU, US, and UK sizes require conversion. As a result, the buyer must simultaneously consider the brand, system, and specific model. [38]

Significantly, more than half of the participants did not know their UK size, even though the UK system is regularly used internationally. The authors consider this further evidence that existing designations create unnecessary complexity for consumers. [39]

The problem is particularly noticeable with online shopping. Shoes can't be tried on before ordering, and customers often order several adjacent sizes of the same model, keeping the one they like and returning the others. The authors cite this approach as one of the factors increasing retail costs and the environmental impact of shipping and returns. [40]

As a more transparent alternative, researchers cite Mondopoint, where size is directly related to foot length. However, even switching to millimeters won't completely solve the problem: width and volume information will still need to be added to the length. [41]

Why the size on the box can be misleading

Problem	Consequence
The US, UK and EU use different systems	Complex conversion
Different brands use different pads.	One number sits differently
Half sizes are not available everywhere.	The buyer is forced to change the full size
Often there is only one fullness	Wide/narrow feet are compensated by length
Online purchase without trying on	More returns
Mondopoint	Shows the length more clearly, but the width still needs to be taken into account.

What researchers offer to the footwear industry

The first and most immediate suggestion is to increase the number of width variations within a single size. Currently, many models essentially assume that all feet of the same length have approximately the same circumference. The resulting spread shows that this assumption poorly corresponds to reality. [42]

The second proposal is to revise shoe last sizes based on modern anthropometric data. Mass production uses so-called grading: a single basic last is mathematically increased and decreased in a constant increment. However, different parts of the foot may change with increasing size in a manner that is not as linear as this scheme suggests.

The third direction is clearer labeling. In addition to the standard size, it's possible to indicate the actual foot length the model is designed for and the width option. This would be especially helpful when purchasing online and when switching between American, British, and European sizes. [43]

A fourth possibility is the use of modern 3D scans of large populations. These allow for the analysis of the entire foot geometry, rather than just two or four linear dimensions. This approach could potentially lead to several shoe last types within a single length—for example, for a narrower heel, a wider forefoot, or a higher instep.

Finally, the authors believe that Australia should consider a more standardized approach to sizing, potentially using a system based directly on foot length. However, they emphasize that standardizing length should not detract from the main result of the work—the need to consider width and girth. [44]

Proposed changes

Now	Possible improvement
One size = mostly one length	Length + fullness
One standard width	Several width options
Historical pads	Lasts based on modern anthropometric data
Unclear EU/US/UK conversion	Transparent actual measurements
Estimation mainly of length	Accounting for three-dimensional shape
Small number of populations during development	Ethnically diverse samples

What does this mean for the buyer today?

The first practical conclusion is that you shouldn't treat your size as a fixed characteristic like your blood type. If a person typically wears an EU 39, it's perfectly normal for a 38 to fit one manufacturer and a 40 to fit another. Research shows that the system itself isn't standardized enough to expect perfect consistency. [45]

The second conclusion is that when trying on shoes, it's important to consider more than just the space in front of the toes. If the length seems right but the forefoot feels tight, going longer isn't the only solution. If the manufacturer makes a wide or extra-wide fit, it's best to try the same size in a different width first.

The third principle is to focus on the larger foot. A difference in length between the right and left feet was extremely common, present in 93 of the 107 participants. It is advisable to try on both shoes and walk in them for a few minutes, rather than evaluating them while sitting or on one foot. [46]

The fourth point is especially important when buying online: it's more helpful to look not only at the letter or number, but also at the manufacturer's chart with the actual foot length. If the brand specifies the insole width, width, or forefoot circumference, this information can be just as important as the actual size.

In cases of chronic pain, severe toe deformities, diabetes, decreased foot sensitivity, or recurring skin injuries, shoe selection becomes a medical issue. The new study doesn't provide clinical guidelines, but its results explain why, in such situations, simply telling the patient to "buy shoes that fit" isn't enough.

What the study does not allow us to state

The first important caveat is that the study included only 107 women. This is an informative sample for an anthropometric pilot analysis, but it is not large enough to accurately determine the size distribution among all the millions of women in Australia. [47]

The second problem is that the participants were recruited in Melbourne using convenience and purposive sampling, not a random national sample. Therefore, the headline "most Australian women wear the wrong shoes" should be taken with caution. More precisely, most women in the sample were wearing a size different from their calculated shoe length.

A third limitation is that the researchers compared self-reported sizes with sizes calculated using anthropometric rules. They did not conduct a laboratory three-dimensional assessment of the internal geometry of each pair of shoes that the women actually wore. Therefore, "different size" does not necessarily mean that a specific shoe literally fits poorly.

Fourth, the reasons for choosing a larger size are derived from a combination of measurements and fit complaints. The study convincingly demonstrates wide variability in width and girth, but cannot prove that every woman went up a size specifically because of the width. Style, toe shape, heel height, habits, brand, and personal comfort also influence decisions. [48]

Finally, ethnic differences require a much larger sample size. The authors themselves emphasize that the finding among Asian women who complained of tight shoes should be considered a signal for further research, rather than proof of biological differences between the groups. [49]

Strengths and Limitations

Strengths	Restrictions
Real anthropometric measurements	A total of 107 participants
Both feet were measured	One urban agglomeration
Length, width and girth were taken into account	Non-national random sample
An ethnically diverse group	Not enough people to reliably compare ethnic groups
Comparison with real usual size	Self-assessed size may vary between brands
Analysis of US and EU systems	Results are not necessarily the same for all markets

Why work is important

The most interesting finding of the study isn't the 72% figure itself. Similar studies have previously shown that a significant proportion of people wear shoes whose sizes don't match their foot measurements. In a systematic review of previous studies, incorrect shoe length or width fit was found in approximately 63-72% of participants, suggesting that RMIT's finding isn't a random finding. [50]

A new study offers a more specific mechanistic explanation: women may choose the "wrong" size because the market simply doesn't offer the correct three-dimensional size. A single number attempts to simultaneously describe length, width, and circumference, even though these parameters don't vary strictly proportionally across individuals.

In this sense, the problem is similar to clothing sold solely based on a person's height, without taking into account chest, waist, or hip measurements. For footwear, this simplified model has historically become commonplace, so consumers often view their feet, rather than the sizing system, as the problem.

The findings could be particularly significant as online retail grows. According to the authors, approximately 39.5% of footwear sales in Australia were online in 2023. When fitting is not possible, a more accurate sizing system could simultaneously reduce customer discomfort, the number of returns, and associated costs. [51]

The main conclusion of the study can therefore be formulated as follows: foot length is a necessary, but not sufficient, characteristic for good footwear. Width and circumference can vary so significantly that creating multiple width variations within a single size would potentially be more beneficial than further complicating the range solely by length. [52]

The main thing is in the numbers

Fact	Meaning
Participants	107
Age	18-54 years old
City	Melbourne
Ethnic categories	10
Participants with origins from ≥2 groups	24
Different lengths of two feet	93 participants
The size did not match the US system	72%
According to the EU system	65%
Larger US size	59%
Larger EU size	52%
Recurring landing problem	68%
Maximum variation in circumference in one US size	40 mm
In one EU size	37 mm
Possible required number of completeness	≈6-7
Complaints about shoes that are too narrow	25 women
Among them are members from three Asian groups	60%
Online publication date	July 28, 2026

[53]

News sources

Pallaspuro B., Islam S., Tan CSL One size fits small: exploring the shoe size preferences of Australian women and their implications for shoe design. International Journal of Fashion Design, Technology and Education. Published online July 28, 2026. DOI: 10.1080/17543266.2026.2709095.

The study was conducted by researchers from the School of Fashion and Textiles, RMIT University, Melbourne, Australia. The authors disclosed no potential conflicts of interest. The study data are available from the corresponding author upon request. [54]

For the medical context, a previously published review is important:

Buldt AK, Menz HB. “Incorrectly fitted footwear, foot pain, and foot disorders: a systematic search and narrative review of the literature.” Journal of Foot and Ankle Research. 2018;11:43.
DOI: 10.1186/s13047-018-0284-z. He showed that in previous studies, 63–72% of participants wore shoes that were incorrectly fitted in length or width, and that poor fit was associated with pain and a range of foot disorders.

Original article by Taylor & Francis

RMIT University's announcement of the research