Each country was graded on labor participation, health, political empowerment and educational attainment.
According to data, only 32 women participate in the labor force for every 76 men.
The global average full-time salary for a working woman is $11,102 a year, just over half the male average of $20,554. According to the WEF, the gender gap in the United States has grown over the past year. More research this week showed the pay gap between men and women exists in 90 percent of sectors.
While the world has made progress closing the gap between women and men in health, education, economic participation, and political empowerment over the last decade, the United States is not keeping up. It has actually regressed on Economic Participation and Opportunity and is the world's least-improved country on the Health and Survival subindex. Eighty-eight percent of women in Rwanda have jobs, compared to 66 percent of USA women.
Other countries that populated the bottom of the list include Mali, Lebanon, Morocco, Jordan, Iran, Chad, Syria and Pakistan.
There has been great progress in women's education worldwide, with more women than men now enrolling at university in 97 countries.
"The Index does not seek to set priorities for countries, but rather to provide a comprehensive set of data and a clear method for tracking gaps on critical indicators so that countries may set priorities within their own economic, political and cultural contexts", Schwab says in the report's preface.
"Companies and governments need to implement new policies to prevent this continued loss of talent and instead leverage it for boosting growth and competitiveness", Zahidi said in a statement.
The so called "gender gap" is narrowing. For the first time since the WEF began quantifying the gap in 2006, Slovenia broke into the ranks of the Top 10 countries with the most equality between the sexes, alongside countries such as Iceland (No. 1), Rwanda (6), and Switzerland (8).
The figure is equally concerning in Turkey, where the number of female deputies represented in parliament hit a record following the June 7 general elections with only 95 deputies out of 550.
The USA fell in its rankings because of slightly less perceived wage equality and changes in ministerial level positions, says the report.
Ten countries-Austria, the Bahamas, Brazil, France, Finland, Guyana, Latvia, Lesotho, Nicaragua, and Namibia-have fully closed the gap on both the health and education.
Turkey ranked 109th in terms of women serving as legislators, senior officials and managers in business life, with 87 percent of those holding key positions in professional life consisting of men.