Saving for retirement sounds impossible if you're loaded down with student loan debt, but it doesn't have to be.

The average student loan debt in the U.S. is $32,731, according to ValuePenguin, a personal finance website.

In comparison, millennial workers have a median of $23,000 saved in all retirement accounts, according to the Transamerica Center for Retirement Studies.

A budgeting tip known as the "50-20-30 rule" allows you to split your paycheck and work toward crushing multiple financial goals, said Brittney Castro, a certified financial planner and CEO of Financially Wise in Los Angeles.

"See how much you can realistically start investing for your future while still working on debt reduction and building cash," she said.

Under the 50-20-30 rule, half of your after-tax pay goes toward fixed expenses, such as your rent or mortgage and utilities.

Twenty percent goes into savings, including building your emergency fund and debt repayment.

The remaining 30% can go toward discretionary spending, including your hobbies and other fun expenses.