You might choose to break down your expenses even further, between things you need to have and things you want to have. For instance, if you drive to work every day, gasoline probably counts as a need. A monthly music subscription, however, may count as a want. This difference becomes important when it’s time to make adjustments.
Step One: Calculate Your After_Tax Income. Your after_tax income is what remains of your paycheck after taxes are taken out, such as state tax, local tax, income tax, Medicare, and Social Security. If you're an employee with a steady paycheck, your after_tax income should be easy to figure out. Look at your paystubs. If health care, retirement contributions, or any other deductions are taken out of your paycheck, add them back in.