Forbes.com has released its annual list of Sisters Doing It For Themselves The World’s 100 Most Powerful Women. Our leading lady, Prime Minister Julia Gillard came in at Number 23. Other notable Australian mentions include billionaire mining tycoon Gina Rinehart who drilled in at a rock-solid Number 19 and Westpac CEO Gail Kelly who banked in at an easy Number 32. As Number 18, Beyoncé Knowles once said, ‘I worked hard and sacrificed to get what I get. Ladies, it ain’t easy bein’ independent.’

Ever wondered how the powers at Forbes go about assembling these definitive lists of power ladies, dudes, celebrities and people with money? Founding editor of ForbesWoman.com, Caroline Howard explains the grueling selections process as follows:

Applying our methodology to a preliminary group of nearly 200 candidates from around the world, we selected the 100 most influential women from six categories or power bases: billionaires, business, lifestyle (including entertainment and fashion), media, nonprofits and politics.

To determine the rank within each category, as well as overall rank on the list of 100, we applied three metrics: dollars, a traditional and social media component and power base points. For money, we looked at the past year in company revenue for women in business and media, salary using the ranking on the May 2011 FORBES Celebrity 100 for lifestyle, GDP for politics and net worth from the March 2011 FORBES World’s Billionaires list for those with 10 figure bank accounts. Women from nonprofits and NGOs were rated on dollars spent fulfilling the organization’s mission statement.

The second component accounts for news hits (Factiva) and TV and radio appearances (Nexis) from the past 12 months, plus social media: Facebook fans, Twitter followers and YouTube views, all as of August 2011. Finally, we scored our candidates on their “reach” or the power bases they impact.

Complicated stuff. Girl I didn’t know you could get down like that.

Via Forbes.com