From the airport
Porvoo is situated near the Helsinki-Vantaa airport.
An example schedule for a September Sunday is as follows:
The drive to Porvoo directly from the airport takes about 30 minutes and a taxi costs around 60-70 €.
You can easily get to Porvoo by bus from Helsinki, there is frequent bus service daily. From the centre of Helsinki the bus trip to Porvoo takes about 50 minutes.