European travel firm GoEuro looked into issues such as how easy it is to get a passport, which countries it offers access to without a visa, its price and how long it is valid for. Their study suggested that a passport from Sweden is the most powerful in the world, followed by Finland, Germany, the UK and the US.
While those with a passport from any of these top five nations can enter 174 countries without a visa, Sweden's came out the cheapest. It costs the equivalent of $43 (€40, £28, 350 kronor). By contrast, a German passport is priced at $69 (€64, £46, 600 kronor) and British passports are priced at around $110 (€102, £72.50, 957 kronor).
The research suggested that EU membership is a vital factor for visa free movement, with Spain, Belgium and the Netherlands also making the top ten.
"In previous rankings it has largely been a matter of analysing visa-free access to determine the strength of a passport. This is an important factor, but it is also crucial to consider the ability of the average citizen to afford purchasing the document," Molly Levinson, a spokesperson for GoEuro told The Local.
"Cost plays a large part in Sweden's ranking. Visa-free access to other countries may be similar to other nationalities but passports in Sweden are much less expensive to obtain."
“The Swedish passport ranks higher based on a combination of visa-free access and ease of obtaining the document. This places Sweden higher than countries such as Switzerland which offers visa-free access to fewer countries and has a more expensive passport."
GoEuro also ranked Sweden highly by comparing the number of hours someone would need to work at the minimum wage to buy a passport. However the figure for Sweden is slightly misleading, since Sweden does not have a minimum wage.
According to Statistics Sweden, the average hourly wage is around $17 (€16, £12, 150 kronor), with some variation according to gender and age group. For someone aged 18 working in retail, the minimum collectively agreed salary is about $13 an hour (€13, £9, 117 kronor).
For someone earning this amount, it would take around three hours to earn enough to buy a passport, which still compares favourably to other countries.
Neighbouring Denmark was ranked sixth by GoEuro, with Danes able to visit 173 different nations without a visa. Unlike Swedes, they need separate paperwork to enter Rwanda.
Sweden has previously performed well in several other passport rankings. Last week it was ranked among the seven most powerful nations in a new global Passport Index and earlier this year it came joint top of the Henley & Partners Visa Restrictions Index, carried out by UK researchers.
Swedish passports are known to be hot property on the black market. A report in 2014 suggested that they are changing hands for as much as 80,000 kronor ($12,200) and are being routinely used for human trafficking, prompting a government investigation.
Sweden's passports were modernized in 2012 and are now considered to be amongst the most difficult in the world to copy. However, under Swedish law a citizen can renew their passport as many times as they like without fear of being questioned by the police. As a result a valid passport could be easily used by a person who looks similar to the official bearer.