The average European accesses the net 16.5 days in a month, and spends 24 hours viewing 2,662 web pages, according to tracking firm comScore.
The Netherlands has the highest net penetration, with 83% of the country online, the firm reported.
Russia, which was included as a European state, has the lowest, at 11% of the population.
More than 221m people across the 16 countries surveyed are online each month, comScore said.
Germany had the largest online population, with 32.5m net users aged 15 and above, the survey for net usage in May 2007 found.
The UK had the most active online population, spending more than 34.4 hours online each month and a peak of more than 21.8m people online in any given day.
Google was the most popular online destination in 13 of the 16 countries, followed by Microsoft in second place and Yahoo in third.
Internet penetration across Europe was 40% of the population aged 15 and above, with only Spain (39%), Italy (36%) and Russia (11%) falling below this level.
Bob Ivins, managing director of comScore Europe, said: "Increased net usage is tied to broadband roll-out. The UK is an example of a country whose net usage has increased dramatically as broadband has reached more people."
He said: "While the study reflects average net usage and penetration, 20% of users account for 60% of usage, with some people spending hundreds of hours online each month."
He added: "As convergence takes place between TV and the internet, the nature of what is classed as online and offline will also have to change.
"Is someone online when watching TV over the net?"
According to comScore, the United States has 156m people online, with 121m online on average each day.