Believe it or not, the average American will spend millions of dollars over their lifetime — $3.3 million to be exact, according to a new study by OneMain Financial. The study utilized data on the average lifespan and average income to determine how much Americans spent on expenses including housing, their car, vacations and more during their entire adult lives.Read: Grant Cardone: Here’s How To Become Rich If You’re Earning an Average SalaryFind Out: How I Make $5,000 a Month in Passive Income ...