Cybercrime will cost the UK economy some £1.9bn this year, says Symantec.
According to the security firm, this equates to £103 for every person affected.
As a result, Symantec has launched the Norton Cybercrime Index, a tool designed to alert web users to the most dangerous sites and search terms, as well as the most popular scams, spam emails and ways criminals commit ID fraud.
The index, which can be viewed online, from mobile devices or within Version 5.0 of Norton 360 - Symantec's latest security suite, also launched today - generates a number based on how high the day's internet security threat level.
Symantec said the number is calculated using an algorithm that uses data from Symantec's Global Intelligence Network, which monitors more than 130 million servers worldwide to keep track of new threats and attacks, along with data from consumer risk management firm ID Analytics, and DataLossDB, a research project from the Open Security Foundation.
As well as checking its Cybercrime Index everyday, Symantec advised web users to use strong passwords on a regular basis, be wary of the personal information they post on social networks and protect their PC.