You might spend more on "wants" than you think. A threadbare minimum of warm clothing is a need. Anything beyond that, such as shopping for clothes at the mall rather than at a discount outlet, qualifies as a want. Yes, the rules are tricky, but if you think about it, they make sense.
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.