Japan Population Decline Simulator

Nagano長野県

Komoro 小諸市

Data last updated:

Komoro, Nagano, Japan has a population of 40,185 (2025 national census). IPSS projections estimate 37,041 by 2030 and 28,582 by 2050 (a decrease of about 30.3% from 2020), with the share of residents aged 65+ rising from 33.8% in 2020 to 46.2%.Sources: Japan Census (Statistics Bureau), IPSS Regional Population Projections (2023)

2025

(Census)

40,185

2030

(Projection)

37,041

▼ -9.6%

2040

(Projection)

32,867

▼ -19.8%

2050

(Projection)

28,582

▼ -30.3%

Change vs. 2020 census

Elderly Rate (65+): 2020 33.8%→2050 46.2%

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Other municipalities in Nagano (長野県)

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.

Komoro 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
198042,355▲ +3.3%Census
198543,705▲ +6.6%Census
199044,888▲ +9.5%Census
199545,711▲ +11.5%Census
200046,158▲ +12.6%Census
200545,499▲ +11.0%Census
201043,997▲ +7.3%Census
201542,512▲ +3.7%Census
202040,991—Census
202540,185▼ -2.0%Census
203037,041▼ -9.6%Projection
203534,995▼ -14.6%Projection
204032,867▼ -19.8%Projection
204530,698▼ -25.1%Projection
205028,582▼ -30.3%Projection

About Komoro

Overview

Komoro (小諸市) is a municipality in Nagano, Japan, with a population of 40,185 as of 2025.

Population Projection of Komoro

According to projections by Japan's National Institute of Population and Social Security Research (IPSS), Komoro's population is expected to reach 37,041 by 2030 (-9.6%), 32,867 by 2040 (-19.8%), and 28,582 by 2050 (-30.3%). A significant population decline is projected over the next three decades.

Aging Rate of Komoro

The aging rate (percentage of residents aged 65 and over) is 33.8% as of 2020 and is projected to rise to 46.2% by 2050. Over 40% of residents will be elderly, significantly affecting healthcare and social services needs.

National Comparison

Komoro's population decline rate exceeds the national average.

National and Prefectural Rank

  • Population decline rate: Ranked #1047 out of 1903 municipalities nationwide.
  • Aging rate in 2050: Ranked #808 out of 1903 nationwide.
  • Population size: Ranked #780 out of 1917 nationwide.
  • Related: National rankings / All municipalities in Nagano

Earnings in Nagano (長野県): Average salary in Nagano (長野県) by age, gender and company sizejpsalary / MHLW Basic Survey on Wage Structure

Frequently Asked Questions

Q.What is the current population of Komoro, Nagano?
A.According to the 2025 national census, Komoro has a population of 40,185.
Q.What is the population of Komoro in 2026?
A.Komoro's population in 2026 is estimated at approximately 39,556. This is an interpolated reference value between the 2025 census (40,185) and the IPSS projection for 2030 (37,041).
Q.What is the projected population of Komoro in the future?
A.According to IPSS projections, Komoro's population is expected to be 37,041 in 2030, 32,867 in 2040, and 28,582 in 2050.
Q.What is the population decline rate of Komoro?
A.Over the 30 years from 2020 to 2050, Komoro's population is projected to change by -30.3%. The 10-year change is -9.6% and the 20-year change is -19.8%.
Q.Why is the population of Komoro 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 Komoro, the share of residents aged 65+ is projected to rise from 33.8% to 46.2% by 2050, which further accelerates natural decrease.
Q.What is the aging rate of Komoro?
A.Komoro's aging rate (percentage aged 65 and over) is 33.8% as of 2020, projected to rise to 46.2% 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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