Let's make the split make sense. Pick what you're splitting, add the people and the expenses, and choose how to divide it. Your results update live as you type.
This sets up the right expense fields for you.
Add everyone involved. You can rename them — it makes the results easier to read.
Enter the total for each shared cost.
Because fair does not always mean 50/50.
See answers on splitting rent, bills, and vacations by income.