Your 20s are often full of firsts: First full-time job, first apartment, first time handling your own finances.
But while it's tempting to reward yourself for your successful adulting by splurging on dinners out or trips abroad, it's important to use your 20s to set up a solid financial foundation for yourself as well.
At face value, that's a lot. But let's break it down: That 25 percent not only includes direct contributions to a 401(k) or Roth IRA, but any company match you receive and any cash savings, including an emergency fund. Greene says you can also count any funds you're putting toward credit card debt and student loans in that percentage as well.