The UK has one wi-fi hotspot for every 11 people and worldwide there is one for every 150, new research from wi-fi provider iPass indicates.
It suggests there will be 47.7 million public hotspots worldwide by the end of 2014.
France currently has the most hotspots, followed by the US and UK.
Hotspots are designed to fill the gaps in coverage left by mobile networks and are often offered free of charge.
The study is one of the first comprehensive looks at the distribution of global wi-fi. A clickable map of hotspots around the world shows the numbers in each region and where they are located - in homes, on trains, planes, airports and retail outlets.
Over the next four years, global hotspot numbers will grow to more than 340 million, the equivalent of one wi-fi hotspot for every 20 people on earth, the research finds.
But this growth will not be evenly distributed. While in North America there will be one hotspot for every four people by 2018, in Africa it will be one for every 408.
While Europe currently has the most dense wi-fi coverage, Asia will overtake it by 2018, according to the report.
The research suggests that the vast majority of hotspots - nearly 34 million - are in homes. These hotspots are part of a growing trend to extend home wi-fi to the local community.
Increasingly firms such as BT are turning home wi-fi routers into public wi-fi hotspots which will provide free net access to other subscribers to the network.
It does so without affecting the bandwidth allowance of the customer whose home it is in.
US provider Comcast caused controversy when it introduced its public home wi-fi service in the summer because customers were not given the option to opt out before receiving it.
Such "homespot" public wi-fi will see explosive growth rising to more than 325 million in 2018 and taking wi-fi "from the cities to the suburbs", according to the research.
"Every second home you walk past will be a public hotspot that you can use if you are part of that provider's network," said June Bower, chief marketing officer at iPass.
There are nearly 7.5 million hotspots in shops, cafes and hotels and and a much smaller number - nearly 11,000, on trains, planes and in airports. But wi-fi on transport is also set to grow massively, the report indicates.
Unlike the mobile network, which tends to be run by three or four big players in each country, wi-fi hotspots are controlled by many different providers.
According to the research, more than 50% of all commercial hotspots are controlled by brands whose core business is not telecommunications.
Run by cafes, hoteliers and retailers, it can make the network "somewhat chaotic", according to Ms Bower.
"At the moment you have to have a separate log-in for every hotspot and ultimately the winning providers are those that will offer the easier access experience," she said.
And there is opportunity there for the big technology brands.
"Everyone has a Google log-in. Google could become a hotspot provider as could Facebook or Apple."
In fact Google is already dabbling in the wi-fi market.
In 2013, it made a deal with Starbucks to offer free wi-fi to 7,000 coffee shops in the US and it recently filed a request with the US Federal Communications Commission to test high-speed wireless spectrum at several locations in California.