Figure out square footage of the common areas, the bedrooms, and sum it up. Say the common areas equate 33% = $1200 = $200 per person. Then (3600 - 1200) / 4 bedrooms = 600 ... but when 2 girls in a bedroom, they only pay $300 each. Of course, some consideration needs to be given to utility use, if each bedroom has its own bathroom, etc. {Does someone get a parking place, and others don't?}

Do the computations, put them in writing, and have everybody sign. Also come to an understanding about due dates, late payments, etc. {and keep the numbers fairly simple and round, except for one person. (example) $599.14 is a pain to write out on a check every month, as per this accountant.}

Divide the rent by 4, 1 share per bedroom. The girls who share will each pay half what the girls who don't share pay. They will have half the personal space and half the closet space so it seems fair to me. Divide the utilities, heat, water, sewer, phone and etc by 6 and then do the math for each share since everyone gets equal benefit from those things.

So 6 people? So that's about 16.7% a person. So maybe the two single roomers pay 19%, and thus the others 15.5% each.

Or single roomers pay about $683 and the others about $557

PAL is 100% correct.

So, the total cost per month in our 4 bedroom apartment is $3594.84 per month. Divided equally it's $599.14 per person per month, however two girls would have their own rooms and four would be sharing rooms. How can we split the cost so it's fair?