For anybody interested in analyzing urban activities, the first task should be to define urban areas. The legal definition of a city is a natural starting point, but many urban activities extend beyond jurisdictional boundaries. For example, many workers in large metropolitan areas commute from suburban jurisdictions to central cities. We therefore need a definition of an urban area within which most of everyday activities are carried out. An urban area typically consists of a core area with significant concentrations of employment and surrounding densely settled areas with close commuting ties with the core.
In the U.S. the Federal Government has defined metropolitan areas since 1947 and provides a variety of statistical data for them. There is no counterpart in Japan and the only metropolitan area definitions that are available are those proposed by a few researchers. Kanemoto and Tokuoka proposed a new metropolitan area definition (UEA) that can cope with complicated interaction patterns in Japanese metropolitan areas. Researchers affiliated with the Center for Spatial Information Science at the University of Tokyo have been constructing the database for UEAs.

The Urban Employment Areas (UEAs) are proposed by Kanemoto, Y. and K. Tokuoka, (2002), " Proposal for the Standards of Metropolitan Areas of Japan ," Journal of Applied Regional Science No.7, 1-15, (in Japanese). The name comes from the fact that they are based on employment patterns. The UEAs are divided between Metropolitan Employment Areas (MEAs) and Micropolitan Employment Areas (McEAs) according to their sizes.
The UEA has the following three major characteristics.
　 (1) The core is determined by the size of the DID (Densely Inhabited District) poluation.
　 (2) The outlying municipalities of a UEA are defined mainly by the condition that 10% or more of employed workers commute to the core.
　 (3) The core of a UEA may contain multiple central municipalities.
A Metropolitan Employment Area (MEA) is a UEA whose core has a DID population of at least 50,000 and a Micropolitan Employment Area (McEA) is that with a DID population of at least 10,000 and less than 50,000.

For the detailed methodology, please refer to the manual and source code below.

Manual (revised July 2026) (Note: There is a typographical error in the Futaba Town code. The correct code is "07546", not "05746".)
Source Code

Available UEA Datasets

UEA datasets are constructed every five years based on the Population Census. The following five datasets are currently available.

Clicking on each year opens a list of core and surrounding municipalities.

These UEAs are constructed using a consistent methodology and are therefore comparable across census years.

Note: When constructing the 2020 UEA, the UEAs for earlier census years were also reconstructed. The 2010 and 2015 UEAs may therefore differ slightly from the versions previously published on this site due to minor methodological refinements. For the previous data, please see here.

Note: Following comments from Ryo Fukuda (Kyushu University), the UEA construction procedure has been partially revised. Accordingly, the UEAs from 2000 to 2020 have been re-estimated.

The preparation of the published UEA datasets was assisted by Shota Nakayama (Ph.D. candidate, Graduate School of Frontier Sciences, The University of Tokyo).

This research has been supported by the Grants-in-Aid for Scientific Research of the Ministry of Education, Culture, Sports, Science and Technology, No.10202202 from 1998 to 2003, No.1661002 from 2004 to 2005 and JSPS KAKENHI Grant Number 15H03344 from 2015 to 2018.