How do you use an LBO model to value a company, and why do we sometimes say that it sets the “floor valuation” for the company?

You use it to value a company by setting a targeted IRR (for example, 25%) and then back-solving in Excel to determine what purchase price the PE firm could pay to achieve that IRR.

This is sometimes called a “floor valuation” because PE firms almost always pay less for a company than strategic acquirers would.