As she reported on sexual harassment issues at big companies, Jennifer Saba, a Breakingviews columnist, looked for a concrete way to quantify the gender gap in the technology sector. Saba decided to focus on Facebook (FB.O), Google (GOOGL.O) and Apple since all of the Silicon Valley companies have a predominately male workforce and publish reams of data on hiring practices.

That data is at the core of the latest Breakingviews calculator, which crunches the numbers and finds that it could take nearly a decade or longer to reach gender parity at Facebook, Google and Apple. Users can input data on their employers to see how long it would take for women to make up half of a company’s workforce.

Since the companies would not divulge employee turnover, Saba used a baseline assumption of 20 percent, broadly in line with the technology industry.

She also looked at current female workforce, female new hires and workforce annual growth. “Simplicity makes it sharp,” Saba said. The calculator demonstrated that at Apple and Google it would take 14 and 15 years, respectively, for women to comprise half the workforce. At Facebook, it would take seven years. “All three companies have such an incredible impact in the world, yet they have a dearth of women employees,” Saba said. “A company should reflect its customer, at the very least.”