A parking system including a database having (a) a number of parking spaces in a zone, (b) a ratio having a number of vehicles using a certain parking service from a pre-defined general population divided by a number of vehicles of the pre-defined general population, and (c) a number of vehicles using the parking service and which are currently parking in the zone, and a calculator configured to calculate from the database an estimation of available parking spaces within the zone, thereby enabling a user to obtain information regarding availability of parking spaces in given locations, compared with other locations.