Japan Population Decline Simulator

Okayama岡山県

Ibara 井原市

Data last updated:

Ibara, Okayama, Japan has a population of 35,310 (2025 national census). IPSS projections estimate 33,205 by 2030 and 23,584 by 2050 (a decrease of about 38.6% from 2020), with the share of residents aged 65+ rising from 37.5% in 2020 to 47.3%.Sources: Japan Census (Statistics Bureau), IPSS Regional Population Projections (2023)

2025Census

35,310

2030Projection

33,205

▼ -13.5%

2040Projection

28,246

▼ -26.4%

2050Projection

23,584

▼ -38.6%

Change vs. 2020 census

Elderly Rate (65+): 2020 37.5%→2050 47.3%

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Other municipalities in Okayama (岡山県)

Data Sources

  • Portal Site of Official Statistics of Japan (e-Stat)(https://www.e-stat.go.jp/)
  • National Institute of Population and Social Security Research (IPSS), Regional Population Projections (2023 ed.)

* This service uses the e-Stat API but its content is not guaranteed by the Japanese government.

Ibara Population Table (1980–2050)

Population by year: national census results (restated to current municipal boundaries) and IPSS (2023) projections based on the 2020 census.

YearPopulationvs 2020Type
198051,669▲ +34.6%Census
198551,053▲ +33.0%Census
199049,255▲ +28.3%Census
199547,647▲ +24.1%Census
200046,489▲ +21.1%Census
200545,104▲ +17.5%Census
201043,927▲ +14.4%Census
201541,390▲ +7.8%Census
202038,384—Census
202535,310▼ -8.0%Census
203033,205▼ -13.5%Projection
203530,710▼ -20.0%Projection
204028,246▼ -26.4%Projection
204525,871▼ -32.6%Projection
205023,584▼ -38.6%Projection

About Ibara

Overview

Ibara (井原市) is a municipality in Okayama, Japan, with a population of 35,310 as of 2025.

Population Projection of Ibara

According to projections by Japan's National Institute of Population and Social Security Research (IPSS), Ibara's population is expected to reach 33,205 by 2030 (-13.5%), 28,246 by 2040 (-26.4%), and 23,584 by 2050 (-38.6%). A significant population decline is projected over the next three decades.

Aging Rate of Ibara

The aging rate (percentage of residents aged 65 and over) is 37.5% as of 2020 and is projected to rise to 47.3% by 2050. Over 40% of residents will be elderly, significantly affecting healthcare and social services needs.

National Comparison

Ibara's population decline rate exceeds the national average.

National and Prefectural Rank

  • Population decline rate: Ranked #773 out of 1903 municipalities nationwide.
  • Aging rate in 2050: Ranked #734 out of 1903 nationwide.
  • Population size: Ranked #831 out of 1917 nationwide.
  • Related: National rankings / All municipalities in Okayama

Earnings in Okayama (岡山県): Average salary in Okayama (岡山県) by age, gender and company sizejpsalary / MHLW Basic Survey on Wage Structure

Frequently Asked Questions

Q.What is the current population of Ibara, Okayama?
A.According to the 2025 national census, Ibara has a population of 35,310.
Q.What is the population of Ibara in 2026?
A.Ibara's population in 2026 is estimated at approximately 34,889. This is an interpolated reference value between the 2025 census (35,310) and the IPSS projection for 2030 (33,205).
Q.What is the projected population of Ibara in the future?
A.According to IPSS projections, Ibara's population is expected to be 33,205 in 2030, 28,246 in 2040, and 23,584 in 2050.
Q.What is the population decline rate of Ibara?
A.Over the 30 years from 2020 to 2050, Ibara's population is projected to change by -38.6%. The 10-year change is -13.5% and the 20-year change is -26.4%.
Q.Why is the population of Ibara declining?
A.Nationwide, Japan's population decline is driven by natural decrease (deaths exceeding births) and, in regional municipalities, by net out-migration of young people to major metropolitan areas. In Ibara, the share of residents aged 65+ is projected to rise from 37.5% to 47.3% by 2050, which further accelerates natural decrease.
Q.What is the aging rate of Ibara?
A.Ibara's aging rate (percentage aged 65 and over) is 37.5% as of 2020, projected to rise to 47.3% by 2050.
Q.Where does this population data come from?
A.Historical data is sourced from Japan's national census via the e-Stat API (Statistics Bureau of Japan). Future projections are from the National Institute of Population and Social Security Research (IPSS) "Regional Population Projections 2023".
Q.Is the data up to date?
A.Historical data uses national census results through 2025. Future projections use the IPSS 2023 edition, which is based on the 2020 census.

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