The FAFSA4caster only calculates federal aid for the student
In other words, it doesn’t calculate university scholarships and grants, Parent PLUS Loans or private loans. While you can include those numbers in the FAFSA4caster, they’re not estimated for you.
To get a more accurate picture, you might want to look at the school’s financial aid program as well. Some meet 100% of your financial need, meaning you likely only have to pay the EFC if you choose to attend.