The city of Helsinki, the capital of Finland, can be divided into various sorts of subdivisions. Helsinki is divided into three major areas: Helsinki Downtown (Finnish: Helsingin kantakaupunki, Swedish: Helsingfors innerstad), North Helsinki (Finnish: Pohjois-Helsinki, Swedish: Norra Helsingfors) and East Helsinki (Finnish: Itä-Helsinki, Swedish: Östra Helsingfors). The subdivisions include boroughs, districts, major districts and postal code areas. The plethora of different official ways to divide the city is a source of some confusion to the inhabitants, as different kinds of subdivisions often share similar or identical names.

Boroughs

Helsinki consists of 60 boroughs (kaupunginosa in Finnish; stadsdel in Swedish). The division into boroughs is the official division created by the city council and used for city planning and other similar purposes. Most of the boroughs have existed since the 19th century as numbered parts of the city, and official names were assigned to them in 1959. Five boroughs (numbers 55 – 59) were annexed on 1 January 2009.

Today, each borough is identified by both a two-digit number between 01 and 59 and an official name in both Finnish and Swedish (in some cases they may be identical). In addition, there is an unnumbered borough called Aluemeri that consists essentially only of outer coastal water that doesn't reach to the coast. Boroughs are further divided into quarters (osa-alue) and sectors (pienalue), numbered with three and four digits respectively. Sectors divide further into individual blocks and properties.

List of Helsinki boroughs

This is listed by Finnish names first and the Swedish names in brackets. This is due to the bilinguality of Finland and Helsinki.

Districts

In addition to the borough division, which exists for city planning purposes, the city is also divided into 34 districts (peruspiiri, distrikt) to facilitate the coordination of public services. The districts, which may comprise several boroughs, are organised into eight major districts (suurpiiri, stordistrikt). Different quarters of a borough may belong to different districts, but individual quarters are never divided between boroughs.

The district division was created by a decision of the city council on 13 December 1982, when the number of different subdivisions used by different municipal departments was seen as confusing and problematic. Before the reform, in 1980, there were 101 different divisions used by the departments, of which only 17 corresponded to the official borough division. The new districts came to use within all providers of public services by 1986.

List of Helsinki districts

Other subdivisions

Helsinki is also often unofficially divided into four distinct geographic areas. These have no absolute definitions, but they are roughly as follows.

• Central Helsinki: the southern major district (except Lauttasaari) and the southern part of the central major district.
• West Helsinki: the western major district plus Lauttasaari.
• North Helsinki: the northern and northeastern major districts and the northern part of the central major district.
• East Helsinki: the eastern and southeastern major districts.

The city is also divided into postal code areas numbered between 10 and 99. Postal codes for private residences in Helsinki have the form 00xx0, where the initial '00' shows that the postal code is located in Helsinki, the next two digits show the postal code area, and the final zero indicates that the code is for a private residence (post offices use the number one, and other numbers are set aside for large businesses that have their own postal codes). (See also Postal codes in Finland.)