From the airport it is easy to take a taxi to the city centre. It will cost around 40€ and take about half an hour.
You can also travel by bus from the airport to Helsinki centre.
Helsinki Region Transport provides public transport services between Helsinki Airport and the metropolitan area. The total travel time is around 40 minutes and you can buy your ticket from a ticket machine or the driver. Click here for more information
Finnair city bus also operates between city centre and Helsinki-Vantaa airport from 05:45 to 01:10 every 20 minutes. The cost is 6,20€ and it will take about 30 minutes. Here you’ll find more information.