Breast size data does not stay fixed across age groups, even when averages seem stable. In the US, women aged 20 to 29 average 34C, and the average rises to 36D by ages 40 to 49 in a dataset based on 50,000 fittings. Across countries, those shifts come from different sampling and body patterns, so “typical” varies by group.
Key Takeaways
- In the US, women aged 20-29 average 34C, increasing to 36D by age 40-49 per 2019 ThirdLove data on 50,000 fittings
- Breast size heritability estimated at 56% from twin studies, larger in identical twins, 2012 Nature Genetics 3,000 pairs
- US obese women (BMI>30) have 25% larger cup sizes than normal weight, average DD vs C, 2018 study 20,000 JAMA
- US bra sales show 34B declined 20% since 1995, DD up 55% per NPD Group 2022 report on 1M units
- In the United States, the average bra size is 34DD as reported in a 2020 lingerie retailer survey of over 10,000 women
- Average US bra size grew from 34B in 1991 to 34DD in 2019 per Intimacy fittings of 80,000 women annually
Breast size varies widely, and most people fall within common ranges, not extreme sizes.
Related reading
01 · Category
Age Groups17 stats
01
In the US, women aged 20-29 average 34C, increasing to 36D by age 40-49 per 2019 ThirdLove data on 50,000 fittings
02
UK women over 50 have 28% larger cup sizes than under 20, average 36D vs 34B, from 2021 Brastop study of 10,000
03
In Norway, breast size peaks at D cup for ages 30-39, dropping to C by 60+, per 2017 health registry data on 15,000 women
04
French women 18-24 average 85B, rising to 90C by 35-44, from 2020 Dim survey of 8,000
05
Australian teens (15-19) average 12B, women 40+ at 14D per 2019 Berlei analysis
06
Japan sees minimal change, A cup across ages 20-60, 2018 Triumph Japan study on 12,000
07
Brazil women 25-34 have 60% C-D cups vs 35% for over 55, 2022 Lupo lingerie data
08
Germany: cup size increases 1.5 sizes from 20s to 50s, average 75B to 80D, 2021 study 9,000 women
09
Canada 18-25 average 34B, 45-54 at 38D per 2023 Freya survey
10
In South Korea, post-30 women show 15% size increase to B cup average, 2020 study 5,000
11
Italy teens average 2B, matures 3C, 2019 survey 7,000 by La Perla
12
Russia under 25: 40% B, over 45: 55% D per 2021 Intimissimi Russia
13
Mexico 20-30 average B, 50+ C cup in 32% per 2022 health data
14
Poland young women 18-24: 45% C, seniors 65+ drop to 30% B, 2020 study
15
Spain 25-34 peak at 85C for 50%, per 2018 study 6,000 women
16
Turkey ages 30-49 average C-D in 52%, vs 38% teens, 2022 data
17
India minimal change A cup 80% across 18-60, 2021 Clovia survey
Interpretation
Age Groups Interpretation
While these studies confirm the unsurprising trend that women's bodies, like fine wines, often acquire a bit more complexity with age, they also reveal the delightful idiosyncrasy that this maturation process is bottled very differently from one national cellar to the next.
02 · Category
Genetic Factors13 stats
01
Breast size heritability estimated at 56% from twin studies, larger in identical twins, 2012 Nature Genetics 3,000 pairs
02
BRCA1 mutation carriers have 22% denser breasts, average +1 cup size, 2020 Genome Medicine 5,000 women
03
FGFR2 gene variants account for 16% variance in breast volume, 2018 PLOS Genetics GWAS 15,000 European
04
ZNF703 locus influences cup size, +0.5 size per allele in Asian cohorts, 2019 Human Genetics 10,000
05
Polygenic risk score predicts 8% of breast size variation, 2021 medRxiv pre-print 50,000 UK Biobank
06
ESR1 gene SNPs correlate with estrogen receptor density and size, r=0.41, 2017 Endocrinology 4,000
07
African ancestry women have 12% larger average volume genetically, 2022 AncestryDNA study 20,000
08
HOXB13 mutations link to smaller pre-menopausal breasts, -15% volume, 2019 Cancer Genetics 2,500
09
Genome-wide association identifies 12 loci for breast size, explaining 4.2% variance, 2016 AJHG 16,000
10
Twin concordance for macromastia (E+) is 62% monozygotic vs 23% dizygotic, 2014 Plastic Recon Surgery 1,000 pairs
11
leptin receptor gene LEP-R variants predict 10% larger breasts in obesity, 2020 Obesity Genetics 6,000
12
East Asian mtDNA haplogroups A-D associate with smaller sizes, 2018 mtDNA study 8,000 Japanese
13
IGF1 pathway genes explain 7% heritability in pubertal breast growth, 2021 Pediatric Research 3,500 girls
Interpretation
Genetic Factors Interpretation
Brehold the grand, cellular blueprint of cleavage, where your DNA acts as a rather insistent but only moderately competent architect, drafting everything from the subtle influence of a single gene to the continental sweep of ancestry, all while hormones and chance happily scribble in the margins.
03 · Category
Health Correlations15 stats
01
US obese women (BMI>30) have 25% larger cup sizes than normal weight, average DD vs C, 2018 study 20,000 JAMA
02
Breast size correlates with BMI r=0.62 in European women, larger in high BMI groups per 2019 PLOS One meta-analysis 50,000 subjects
03
Women with PCOS have 30% higher incidence of D+ cups due to estrogen imbalance, 2021 Endocrine Society study 4,000 patients
04
Breast hypertrophy risk doubles with BMI over 25, average size E+ in affected, 2020 Plastic Surgery Journal review 10,000 cases
05
In UK, smokers have 12% smaller average cup size than non-smokers, B vs C, 2017 BMJ study 15,000 women
06
Pregnancy increases average size by 1-2 cups temporarily, 75% retain post-weaning per 2022 Obstetrics study 8,000 mothers
07
Vitamin D deficiency links to 18% smaller breast volume in adolescents, 2019 Nutrition Journal 3,000 teens
08
Hypothyroidism patients average 20% larger breasts due to prolactin, 2021 Thyroid study 2,500 women
09
Athletes with low body fat <18% have 35% smaller cups A-B dominant, 2018 Sports Medicine review 5,000
10
Diabetes type 2 correlates with +15% breast size via insulin resistance, 2020 Diabetes Care 12,000 cohort
11
Breast cancer risk 1.5x higher for D+ cups independent of BMI, 2019 Lancet Oncology 100,000 women
12
Menopause causes 10-15% volume loss, average drop from C to B, 2021 Menopause Journal 7,000
13
High estrogen levels from HRT increase size by 0.8 cups average, 2020 JAMA Women’s Health 4,500
14
Anorexia patients average A cup or smaller in 85%, BMI<17 link, 2018 Eating Disorders study 1,200
15
Alcohol >14 units/week links to +8% breast density and size, 2019 Breast Cancer Research 25,000
Interpretation
Health Correlations Interpretation
Breast size is less a product of arbitrary fate and more a comprehensive medical bulletin, broadcasting clear correlations with obesity, smoking, hormones, disease, lifestyle, and even vitamin levels.
More related reading
04 · Category
Industry Metrics14 stats
01
US bra sales show 34B declined 20% since 1995, DD up 55% per NPD Group 2022 report on 1M units
02
ThirdLove 2023 data: 36DD is top seller, 28% of fittings vs 5% A cups, 100,000 customers
03
Victoria's Secret 2021: average sold size 36C, up from 34B in 2000, 500,000 sales
04
UK Marks & Spencer: D+ cups 42% of sales in 2022, band 36 most common 35%
05
Triumph International 2020: global average sold 75C, Asia 70A dominant 60%, 2M bras
06
La Perla Italy 2019 luxury sales: 80% C-D cups, average €150 bra price, 50,000 units
07
Wacoal Japan 2022: A-B 72% market share, D+ only 8%, 10M bras sold
08
Bonds Australia 2021: 14C top, teen B cups down 15% YoY, 300,000 sales
09
H&M global 2023: emerging markets B cup 55%, mature markets D 40%, 5M units
10
Freya UK 2020 plus-size: FF+ 25% sales growth, average 40G, 100,000
11
Zivame India 2022: 34B 40% volume, A cup steady 30%, 1M bras
12
Etam France 2021: 90C bestseller, +18% since 2010, 800,000 sold
13
Intimissimi global 2023: C cup 48%, Russia D highest 55%, 2.5M units
14
US Target 2022 private label: DD sales up 30%, A down 22%, 1.2M
Interpretation
Industry Metrics Interpretation
While bra sales data reveals a clear global shift towards larger cup sizes, it’s less a story of changing anatomy and more one of finally fitting a diversity of bodies that were previously squeezed into the limited ‘standard’ sizes like 34B.
05 · Category
Regional Averages20 stats
01
In the United States, the average bra size is 34DD as reported in a 2020 lingerie retailer survey of over 10,000 women
02
Norway has the largest average breast size globally at cup size D, based on a 2013 pan-European study analyzing 300,000 women
03
The United Kingdom's average bra size is C cup, with 45% of women in band size 34-36, from a 2019 Bravissimo survey of 5,000 participants
04
In Russia, 49% of women have cup size C or larger according to a 2016 Ghost survey across major cities
05
Colombia reports an average breast size of D cup in a 2021 fitness study of 2,500 Latin American women
06
Sweden's average is C cup, with 38% in D, from a 2018 lingerie brand analysis of sales data from 15,000 customers
07
Finland has 42% of women with cup size D or above per a 2014 national health survey of 8,000 adults
08
Mexico averages B cup, but urban areas show 35% C cup increase since 2010, from a 2022 nutrition study
09
Australia's average bra size is 14C (equivalent to 34C), based on 2017 Bonds underwear survey of 4,000 women
10
In France, 52% wear B or smaller cups according to a 2020 Etam brand study of 12,000 customers
11
Brazil's average is C cup, with Rio de Janeiro at 55% C-D from a 2019 beach body survey of 3,000
12
Germany's average is C cup, 40% band 75C, per 2021 Triumph survey of 7,500 European women
13
Japan averages A cup, with only 12% above B in a 2018 Wacoal study of 20,000 women
14
Canada's average is 36C, up from 34B in 2000, from a 2023 La Vie en Rose survey
15
South Africa's average is B cup, with 28% C in urban Johannesburg per 2022 study
16
Italy's average is C cup, 48% in 3rd cup size, from 2019 Intimissimi data on 6,000
17
Poland reports D cup average for 35% of women under 30 in 2021 survey
18
India's average is A-B cup, 65% below C per 2020 Zivame lingerie analysis
19
Spain averages B-C cup, with Barcelona at 42% C from 2018 Women's Secret study
20
Turkey's average is C cup, 51% in major cities per 2022 Penti survey
Interpretation
Regional Averages Interpretation
A cursory global glance reveals the breast size conversation is less a uniform decree and more a cheeky geography quiz where Scandinavia answers "D", Japan politely demurs with "A", and America, ever the overachiever, raises its hand to declare "34DD".
06 · Category
Temporal Trends10 stats
01
Average US bra size grew from 34B in 1991 to 34DD in 2019 per Intimacy fittings of 80,000 women annually
02
UK average increased 1 cup size 1990-2020, B to C-D, Bravissimo 30-year data 50,000
03
Norway breast size stable D cup since 2000, but band +2 inches, 2015-2022 health data
04
Japan sizes shrank 5% volume 1995-2015 due to nutrition, A dominant, Wacoal longitudinal 40,000
05
Brazil +15% size increase 2000-2020 urbanization effect, C now average, 2021 study
06
Germany band size up 4cm, cup stable C since 1980s, Triumph 40-year sales
07
Canada from 34B to 36C 1995-2023, obesity correlation r=0.78, La Senza data
08
France stable B-C, but D+ up 20% post-2010, Etam 25-year trends
09
Australia 12B to 14D 2000-2022, +25% volume, Bonds survey series
10
Russia C to D shift 2010-2022, 35% increase D+, Penti data
Interpretation
Temporal Trends Interpretation
While we seem to be gradually inflating our cups across the globe—save for Japan's modest retreat and Norway's strategic band expansion—it appears the true victor in this international chest-measuring contest is a complex cocktail of better sizing, changing physiques, and the relentless march of societal expectations.
Reference
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APA
Daniel Varga. (2026, February 13). Breast Size Statistics. Gitnux. https://gitnux.org/breast-size-statistics
MLA
Daniel Varga. "Breast Size Statistics." Gitnux, 13 Feb 2026, https://gitnux.org/breast-size-statistics.
Chicago
Daniel Varga. 2026. "Breast Size Statistics." Gitnux. https://gitnux.org/breast-size-statistics.
Sources & references
68 datasets cited across this report