Two travel bloggers created the Women's Danger Index to rank countries by how safe they are for solo female travelers.

The ranking used eight factors, including homicide rates, legal discrimination, gender inequality scores, and sexual violence rates to determine how safe the 50 most popular tourist destinations are.

South Africa is the most dangerous country for women to visit alone, followed closely by Brazil and Russia, according to the index.

Spain is the safest country for women to travel to on their own, according to the list, while the United States ranked amongst the 20 most unsafe destinations worldwide.

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Traveling on your own can be incredibly empowering, but for women, it can also come with added risks.

Travel bloggers Asher and Lyric Fergusson developed the Women's Danger Index using sources like the Gallup World Poll, UN Women, Georgetown Institute, and World Economic Forum in order to help determine where it is safe for women to travel solo.

The index uses eight factors — safety walking alone at night, intentional homicide of women, non-partner sexual violence, intimate partner violence, legal discrimination, global gender gap, gender inequality, and violence against women attitudes — to evaluate the safety of each of the 50 most popular countries for tourists to visit across the globe.

"Solo female travel has become a hugely popular trend and a lot of times women may go to a place a little bit haphazardly based on things they've heard from friends or seen via glossy Instagram photos," Lyric Fergusson told INSIDER. "We wanted to create a resource for travelers based on actual hard data from trusted international sources rather than relying on hearsay and anecdotal evidence. We're not trying to deter people from traveling to any of these countries but instead want to bring awareness to safety issues that may be present."

The eight factors included in the Fergussons' Women's Danger Index. Asher Fergusson

"All factors were converted into a scale of 0 to 100 with the worst-performing country getting 100 points and all other countries receiving a proportional score based on their corresponding stats for each factor," Asher Fergusson said. "We gave Street Safety and Intentional Homicide of Women a double weighting score because they are very good indicators of safety for foreign female travelers and are more likely to be highly accurate since it isn't 'shameful' to admit if you feel safe walking alone at night in your city."

"Therefore the highest possible score in the Women's Danger Index is 1,000 points when you add up the 8 factors," he added.

According to the index, South Africa is the most dangerous country for women to visit alone, followed closely by Brazil and Russia. Spain, Singapore, and Ireland were the three safest places for solo travel, according to the Fergussons' findings.

"To be able to measure safety for solo female travelers we realized that we couldn't only look at data on street safety, rape, and violence," Lyric said. "We also needed to dive into the general attitude of the culture, the minutiae of the legal system, and other gender inequality issues. This is because these issues can affect everything, from easily getting a taxi alone to having your voice be heard in a conversation to even needing a male escort for your safety."

The Fergussons wrote on their website that they were surprised by the relatively high rankings for both the United States and Australia, which clocked in at 19th and 29th on the list, respectively.

"The fact is that you could have a great experience in a country that ranked poorly on our list or have a scary experience in a country that is considered very safe," Asher said. "It can depend heavily on where you go within a country because one city may be way safer than another city or region."

"No matter where you're going, do your research, learn about local laws and faux-pas, or consider traveling in groups to 'tricky' countries," Lyric said. "Use your common sense and take appropriate precautions."

Check out their full rankings below: