It really is a man’s world.

Even when women and men share identical college majors, females still earn less in their careers, according to a new study released Wednesday by career site Glassdoor.com, which examined recent grads for five years post college. The reason this happens is that women and men with the same major get employed in different jobs after graduation, says Andrew Chamberlain, chief economist with the firm.

This pay gap even happens — and is magnified — when women choose lucrative majors like biology and math. For example, the three most common jobs for a male biology major are lab technician, data analyst and manager, while the three most common for women are lab technician, pharmacy technician and sales associate. (Pharmacy techs and sales associates tend to be lower paying jobs.) Math majors face a similar situation. More men than women in this field work as higher-paying data scientists.

This so-called “job sorting” may partly be due to differing career choices and also because “women aren’t being hired for certain jobs,” Chamberlain says.

15 majors with the biggest pay gaps in the first 5 years

What’s more, Chamberlain points out, is that the gender pay gap tends to get worse — not better — as time goes on. According to a 2016 Glassdoor study, the gender pay gap for workers aged 55-64 is largest among any age group.

But even if it didn’t get get worse, think of what this pay gap could mean over the course of a career. Starting out in her career, a woman in healthcare administration makes $11,250 less a year than a man with a healthcare administration major. Over a 40-year career, that would mean she earned $450,000 less than a man. The lifetime earnings gap for mathematics majors would add up to $432,720 and for biology majors $240,000.

On a more positive note for women, there are a handful of industries where women earn more than men right out of college, including architecture (14% more), music (10.1%) and social work (8.4%).