Migrate from 2010 to 2013 and from web applciation to site collection

We are migrating 20 web applications in 2010 to 2013. Those 2010 web applications will become site collections in 2013. What is the easiest way to do it?

Can I migrate the content databases first and create a new web application in 2013.  Then I use powershell script  New-SPSite with ContentDatabase parameter specidied?

Thanks.