Total area and inhabitable area
Population density divides population by area. The handbook reports both density per total square kilometre and density per inhabitable square kilometre. Both use people per km²; the second divides by the smaller area classified as inhabitable in the source. It does not count where each resident actually lives within the prefecture.
In its 2024 columns, Tokyo has 2,200 km² of total area and 1,429 km² of inhabitable area. The published densities are 6,445 and 9,924 people/km², respectively. Hokkaido has 83,422 km² and 22,691 km²; its published densities are 64 and 222 people/km². These examples show how changing the denominator changes the reported figure; they do not compare neighbourhoods.
What the figures mean
The method is population (people) ÷ area (km²). The population column is printed in thousands, so a calculation from that column first multiplies it by 1,000. The figures above are the source's published densities, rather than densities recalculated from the displayed rounded population and area. Recalculation may differ because the published columns are rounded separately.
The reference year for these population, area and density columns is 2024. Statistical Handbook of Japan 2026 is the publication title and year, not the year of these measurements. The 2020 columns elsewhere in Appendix 1 should not be mixed into this comparison.
Source: Statistical Handbook of Japan 2026, Appendix 1, Statistics Bureau, Ministry of Internal Affairs and Communications, Japan, with the Geospatial Information Authority of Japan. Snapshot reviewed 2026-10-08.