Who has sold more albums Kerry underwood or Kelly Clarkson?

As of my knowledge cutoff in September 2021, here is a comparison of album sales for Kelly Clarkson and Carrie Underwood:

Kelly Clarkson:

- Total estimated album sales: Over 25 million worldwide

Carrie Underwood:

- Total estimated album sales: Over 65 million worldwide

This information may be outdated, and it's always best to refer to the latest official sources for the most up-to-date figures.