Adding…you are a HS sophomore now. At this point you don’t even know if you have the stats to make you a competitive applicant for Brown.
In addition, those Net Price Calculators are currently set up for students enrolling in fall 2021. You won’t be going until fall 2023. So any NPCs you use now aren’t necessarily going to even apply the year you apply to college.
For the 2023-2024 FAFSA and Profile (that will be your freshman year in college) the 2021 tax year info will be used. That year hasn’t even started yet. You don’t really even know what your parent(s)’ incomes will be, right?
And lastly, look on the Brown financial aid section of their website. I’m not sure where you got the info that you can disregard your dad’s income for Brown.