In Japan, the population sex ratio has seen slight changes over the past decades. In 2021, the number of men was around **** for every 100 women, constituting a decrease from **** in 1950.

What is the sex ratio? The population sex ratio is determined by the sex ratio at birth, different mortality rates between men and women, as well as losses and gains through migration. In the absence of alteration, the sex ratio in human populations is quite constant, with only minor deviations. While the sex ratio at birth is usually *** to ***, the population sex ratio, which refers to the total number of males for every 100 females, is often below 100. The reason for the shift mostly lies in differing lifestyles and physical constitutions of men and women. In general, women tend to be more resistant to disease throughout life, while men tend to engage in higher risk behavior or violence.

Influences and consequences
The sex ratio at birth and its possible determinants such as gestation environment, climate change, chemical pollution or socio-economic factors have long been subject to scientific research. Recently the impact of natural disasters, like the nuclear disaster in Japan in 2011, was presumed to influence the sex ratio at birth. The adult gender ratio has long been recognized as a key population-level determinant of behavior. However, there are many different or competing theories in existing literature about the social impacts of gender imbalance on topics such as violence, family stability, reproduction etc.

Japan JP: Sex Ratio at Birth: Male Births per Female Births data was reported at 1.056 Ratio in 2016. This stayed constant from the previous number of 1.056 Ratio for 2015. Japan JP: Sex Ratio at Birth: Male Births per Female Births data is updated yearly, averaging 1.056 Ratio from Dec 1962 (Median) to 2016, with 20 observations. The data reached an all-time high of 1.056 Ratio in 2016 and a record low of 1.056 Ratio in 2016. Japan JP: Sex Ratio at Birth: Male Births per Female Births data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Japan – Table JP.World Bank: Population and Urbanization Statistics. Sex ratio at birth refers to male births per female births. The data are 5 year averages.; ; United Nations Population Division. World Population Prospects: 2017 Revision.; Weighted average;

Actual value and historical data chart for Japan Sex Ratio At Birth Male Births Per Female Births

Japan Sex Ratio: Annual: Inter Prefectural Migrants data was reported at 124.500 % in 2017. This records a decrease from the previous number of 125.600 % for 2016. Japan Sex Ratio: Annual: Inter Prefectural Migrants data is updated yearly, averaging 129.200 % from Dec 1958 (Median) to 2017, with 60 observations. The data reached an all-time high of 141.500 % in 1991 and a record low of 118.900 % in 1959. Japan Sex Ratio: Annual: Inter Prefectural Migrants data remains active status in CEIC and is reported by Statistical Bureau. The data is categorized under Global Database’s Japan – Table JP.G006: Vital Statistics: Migration.

In 2024, around **** percent of Japanese overseas travelers were women, while about **** percent were men. This was the first time in the past decade that the number of women traveling abroad was higher than that of men.

In 2023, the total population in Japan slightly decreased to just below *** million people compared to the previous year, with the female population reaching around **** million, as compared to **** million men. The oldest population in the world  Japanese society is facing severe demographic problems such as decreasing birthrates, remaining under *** million births annually recently, and a thereby aging population. The country’s average age lies at around ** years, making its population the oldest in the world. Elderly people aged 65 years and older accounted for about ** percent of the population in 2023. According to a forecast, this age group would make up approximately ** percent of the Japanese population by 2070. Challenges with the demographic shift The rapid aging of the society poses significant economic and sociopolitical challenges to the country, as the workforce will continue to shrink while increasingly more elderly will receive long-term support. Currently, close to ***** million Japanese require long-term care, leading to national benefit expenses of over ** trillion yen annually, including in-home and community-based services.

Japan Sex Ratio: Intra Prefectural Migrants data was reported at 103.300 % in May 2018. This records a decrease from the previous number of 114.400 % for Apr 2018. Japan Sex Ratio: Intra Prefectural Migrants data is updated monthly, averaging 103.300 % from Jan 1998 (Median) to May 2018, with 245 observations. The data reached an all-time high of 118.500 % in Apr 2009 and a record low of 94.700 % in Nov 1999. Japan Sex Ratio: Intra Prefectural Migrants data remains active status in CEIC and is reported by Statistical Bureau. The data is categorized under Global Database’s Japan – Table JP.G007: Vital Statistics: Migration.

As of February 2025, around ** percent of registered members of the All Japan Judo Federation were male. Gender discrepancies in terms of the number of active sports participants is common in martial arts disciplines.

JP: Population: as % of Total: Female: Aged 0-14 data was reported at 12.256 % in 2017. This records a decrease from the previous number of 12.304 % for 2016. JP: Population: as % of Total: Female: Aged 0-14 data is updated yearly, averaging 18.671 % from Dec 1960 (Median) to 2017, with 58 observations. The data reached an all-time high of 29.143 % in 1960 and a record low of 12.256 % in 2017. JP: Population: as % of Total: Female: Aged 0-14 data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Japan – Table JP.World Bank: Population and Urbanization Statistics. Female population between the ages 0 to 14 as a percentage of the total female population. Population is based on the de facto definition of population.; ; World Bank staff estimates based on age/sex distributions of United Nations Population Division's World Population Prospects: 2017 Revision.; Weighted average; Relevance to gender indicator: Knowing how many girls, adolescents and women there are in a population helps a country in determining its provision of services.

Collective data of Japan's birth-related statistics from 1899 to 2022. Some data are missing between the years 1944 and 1946 due to records lost during World War II.

For use case and analysis reference, please take a look at this notebook Japan Birth Demographics Analysis

Feature Descriptions

• year: The year.
• birth_total: The total number of births.
• birth_male: The total number of male births.
• birth_female: The total number of female births.
• birth_rate: The birth rate. Equation is birth_total / population_total * 1,000
• birth_gender_ratio: The birth gender ratio. Equation is birth_male / birth_female * 1,000
• total_fertility_rate: The average number of children that are born to a woman over her lifetime.
• population_total: The total population.
• population_male: The total male population.
• population_female: The total female population.
• infant_death_total: The total infant deaths.
• infant_death_male: The total male infant deaths.
• infant_death_female: The total female infant deaths.
• infant_death_unknown_gender: The total unknown gender infant deaths.
• infant_death_rate: The infant death rate. Equation is infant_death_total / birth_total * 1,000
• infant_death_gender_ratio: The infant death gender ratio. Equation is infant_death_male / infant_death_female * 1,000
• infant_deaths_in_total_deaths: The infant death ratio among other deaths.
• stillbirth_total: The total number of stillbirths (dead born).
• stillbirth_male: The total number of male stillbirths.
• stillbirth_female: The total number of female stillbirths.
• stillbirth_unknown_gender: The total number of unknown gender stillbirths.
• stillbirth_rate: The stillbirth rate. Equation is stillbirth_total / (birth_total + stillbirth_total) * 1,000
• stillbirth_gender_ratio: The stillbirth gender ratio. Equation is stillbirth_male / stillbirth_female * 1,000
• firstborn: The number of firstborns.
• secondborn: The number of secondborns.
• thirdborn: The number of thirdborns.
• forthborn: The number of forthborns.
• fifthborn_and_above: The number of fifthborns and above.
• weeks_under_28: The number of births occurred under week 28. Early terms.
• weeks_28-31: The number of births occurred between weeks 28 and 31. Early terms.
• weeks_32-36: The number of births occurred between weeks 32 and 36. Early terms.
• weeks_37-41: The number of births occurred between weeks 37 and 41. Full terms.
• weeks_over_42: The number of births occurred over week 42. Late terms.
• mother_age_avg: The mother's average age.
• mother_age_firstborn: The mother's average age of the firstborn.
• mother_age_secondborn: The mother's average age of the secondborn.
• mother_age_thirdborn: The mother's average age of the thirdborn.
• mother_age_under_19: The number of births by mothers under age 19.
• mother_age_20-24: The number of births by mothers between age 20 and 24.
• mother_age_25-29: The number of births by mothers between age 25 and 29.
• mother_age_30-34: The number of births by mothers between age 30 and 34.
• mother_age_35-39: The number of births by mothers between age 35 and 39.
• mother_age_40-44: The number of births by mothers between age 40 and 44.
• mother_age_over_45: The number of births by mothers over 45.
• father_age_avg: The father's average age.
• father_age_firstborn: The father's average age of the firstborn.
• father_age_secondborn: The father's average age of the secondborn.
• father_age_thirdborn: The father's average age of the thirdborn.
• legitimate_child: The Number of births under married parents.
• illegitimate_child: The number of births under non-married parents.

Acknowledgement

E-Stat Demographic Survey

Actual value and historical data chart for Japan Population Ages 0 4 Female Percent Of Female Population

School enrollment, primary (gross), gender parity index (GPI) in Japan was reported at 1.0025 % in 2019, according to the World Bank collection of development indicators, compiled from officially recognized sources. Japan - Ratio of female to male primary enrollment - actual values, historical data, forecasts and projections were sourced from the World Bank on October of 2025.

The representation of women in Japanese higher education continues to grow, with female students comprising **** percent of university enrollments in 2024. This marks a steady increase over the past decade, reflecting changing societal attitudes and educational opportunities for women in Japan. Study field preferences Female students enrolled at universities in Japan exhibit a strong interest in the ***************, with the highest number of female undergraduates majoring in the subject in 2024. At the postgraduate level, the *********** field had the highest number of female students in the same year. When it comes to gender distribution, ******************************************among others, attracted a higher share of women than men in postgraduate studies. Employment prospects The rising female university enrollment is translating into positive career outcomes. In 2024, over 80 percent of female university graduates in Japan entered employment after completing their studies. It is worth noting that this proportion was much lower among women with postgraduate degrees, with below ** percent of those with master’s and doctoral diplomas securing employment after graduation.

Odds ratios of MZT by method of fertilization and parents’ conditions. CT (early cleavage-stage embryo transfer), BT (blastocyst transfer), smoking and alcohol consumption habits at pregnancy recognition, SF-8 score of 50 or less. Low education: defined by the highest academic background and categorized as high school graduation or lower, Low income: defined by the annual revenue of the household and categorized as an annual income of 4,000,000 Japanese yen or less. (XLS 45 kb)

In 2024, the total labor force in Japan was composed of approximately **** million people, among which around ** million were men and close to **** million were women. While the number of men in the workforce declined, the number of women in the labor force increased, resulting in an increase in the total labor force.

School enrollment, primary and secondary (gross), gender parity index (GPI) in Japan was reported at 1.0034 % in 2019, according to the World Bank collection of development indicators, compiled from officially recognized sources. Japan - Ratio of girls to boys in primary and secondary education - actual values, historical data, forecasts and projections were sourced from the World Bank on November of 2025.

Japan Sex Ratio: Internal Migrants data was reported at 113.700 % in May 2018. This records a decrease from the previous number of 125.100 % for Apr 2018. Japan Sex Ratio: Internal Migrants data is updated monthly, averaging 113.500 % from Jan 1998 (Median) to May 2018, with 245 observations. The data reached an all-time high of 131.100 % in Apr 2009 and a record low of 104.400 % in Nov 1999. Japan Sex Ratio: Internal Migrants data remains active status in CEIC and is reported by Statistical Bureau. The data is categorized under Global Database’s Japan – Table JP.G007: Vital Statistics: Migration.

According to a survey conducted in 2020, the most popular matchmaking app among both men and women in Japan was Pairs, with almost ** percent of male and close to ** percent of female respondents having used that app. Tinder, the only non-domestic app in the ranking, was primarily used by men in Japan.

In anurans, female polyandry under male harassment is distributed across taxa because of external aquatic fertilisation. According to the sexual selection theory, male–male competition for access to females is affected by the operational sex ratio (OSR) and population density. The Japanese common toad, Bufo japonicus, is widespread in mainland Japan, and like the European common toad, B. bufo, it engages in explosive breeding. We observed the breeding behaviour of B. japonicus in isolated local populations for three years in two breeding ponds with different population sizes and densities: large-low (L-pond) and small-high (S-pond). We analysed the relative polyandry ratio in egg clutches laid by females and estimated the size-assortative mating pattern to be an indicator of male–male competition in the two ponds. Both ponds tended to exhibit a size-assortative mating pattern; however, the frequency of polyandry was different in the two ponds (L-pond = 20% and S-pond = 90%). We also found that polyandry could occur without multiple amplexus with a high population density, i.e. eggs were often fertilised by free-swimming sperm in the small shallow pond. We propose that high female polyandry ratios without continuous male harassment are generated because of a male-biased OSR and a high population density in the small pond.

【リソース】Volume 1_6-1_Trends in infant deaths, infant mortality rates (per 1,000 live births), sex ratio and proportion of infant deaths to total deaths:Japan / Volume 1_6-2_Trends in neonatal deaths, neonatal mortality rates (per 1,000 live births), sex ratio and proportion of neonatal deaths to infant deaths:Japan / Volume 1_6-3_Infant mortality rates (per 100,000 live births) and percent distribution by sex and age (days, weeks and months):Japan, 2018 / Volume 1_6-4_Trends in infant mortality rates (per 100,000 live births) by sex and age (days, weeks and months):Japan / Volume 1_6-5_Trends in infant deaths and infant mortality rates (per 1,000 live births) by month:Japan / Volume 1_6-6_Live births, infant deaths and infant mortality rates (per 1,000 live births) by months of birth:Japan / Volume 1_6-7_Trends in infant deaths and percent distribution by place of occurrence:Japan / Volume 1_6-8_Percent distribution of infant deaths by place of occurrence:Japan, each prefecture and 21 major cities, 2018 / Volume 1_6-9_Infant deaths, infant mortality rates (per 1,000 live births) and percent distribution by type of occupation of household:Japan, 2018 / Volume 1_6-10_Trends in infant deaths by each prefecture:Japan / Volume 1_6-11_Trends in infant mortality rates (per 1,000 live births) by each prefecture:Japan / Volume 1_6-12_Infant mortality rates (per 100,000 live births) by age and proportion of neonatal deaths:Japan, each prefecture and 21 major cities, 2018 / Volume 1_6-13_Trends in infant deaths and infant mortality rates (per 100,000 live births) by causes (the list of causes of infant death):Japan / Volume 1_6-14_Infant deaths and infant mortality rates (per 100,000 live births) by age and causes (the list of causes of infant death):Japan, 2018 / Volume 1_6-15_Percent distribution of infant deaths by age and causes (the list of causes of infant death):Japan, 2018 / Volume 1_6-16_Trends in leading causes of neonatal and infant death:Japan (deaths, death rates (per 100,000 live births), proportion(%)) / Volume 1_6-17_Infant mortality rates (per 100,000 live births) by causes (the list of causes of infant death):Japan, each prefecture and 21 major cities, 2018 / Volume 1_6-18_Infant deaths and infant mortality rates (per 100,000 live births) by diseases, causes (the list of causes of infant death) and birth weight:Japan, 2018 / Volume 1_6-19_Neonatal deaths and neonatal mortality rates (per 100,000 live births) by diseases, causes (the list of causes of infant death) and birth weight:Japan, 2018 / Volume 2_1_Infant deaths (under 1 year), neonatal deaths (under 4 weeks) by sex and month of occurrence:Japan, urban/rural residence, each prefecture and 21 major cities / Volume 2_2_Infant deaths (under 1 year) by age and sex:Japan, urban/rural residence, each prefecture and 21 major cities / Volume 2_3_Infant deaths (under 1 year) by age, sex and type of occupation of household:Japan / Volume 2_4_Infant deaths (under 1 year) by month of occurrence and date of birth:Japan / Volume 2_5_Infant deaths (under 1 year) from diseases, birth weight and mean birth weight by sex, plurality of birth and age of mother:Japan / Volume 2_6_Infant deaths (under 1 year) from diseases, birth weight and mean birth weight by sex, plurality of birth and birth order:Japan / Volume 2_7_Infant deaths (under 1 year) from diseases, birth weight and mean birth weight by sex and period of gestation:Japan / Volume 3_1_Infant deaths (under 1 year) by causes (the list of causes of infant death), sex and age:Japan / Volume 3_2_Infant deaths (under 1 year) and neonatal deaths (under 4 weeks) by causes (the list of causes of infant death) and sex:Japan, each prefecture and 21 major cities / Volume 3_3_Infant deaths (under 1 year) and neonatal deaths (under 4 weeks) by causes (the list of causes of infant death), sex and month of occurrence:Japan / Volume 3_4_Infant deaths (under 1 year), neonatal deaths (under 4 weeks) and early neonatal deaths (under 1 week) from diseases by causes (the list of causes of infant death), sex and birth weight:Japan / Volume 3_5_Infant deaths (under 1 year), neonatal deaths (under 4 weeks) and early neonatal deaths (under 1 week) from diseases by causes (the list of causes of infant death), sex and specified period of gestation:Japan / Vital Statistics_Vital statistics of Japan_Final data_Infant mortality_Yearly_2018 / Volume 1_6-1_Trends in infant deaths, infant mortality rates (per 1,000 live births), sex ratio and proportion of infant deaths to total deaths:Japan,Volume 1_6-2_Trends in neonatal deaths, neonatal mortality rates (per 1,000 live births), sex ratio and proportion of neonatal deaths to infant deaths:Japan,Volume 1_6-3_Infant mortality rates (per 100,000 live births) and percent distribution by sex and age (days, weeks and months):Japan, 2018,Volume 1_6-4_Trends in infant mortality rates (per 100,000 live births) by sex and age (days, weeks and months):Japan,Volume 1_6-5_Trends in infant deaths and i