“I divide, you choose.”
My mother taught me this basic rule for splitting stuff, usually some yummy cake or ice cream. Inherently fair, the divider makes sure both pieces are equal, while the chooser is assured that she will be able to pick the one she thinks is best.
When sharing apartments, though, it’s a little harder to figure out who gets to divide it and who pays what rent. If you’re someone who likes things to be worked out “scientifically,” there’s an on-line calculator for you. Splittherent.org is the brainchild of Jonathan Bittner, a side project to his studies to be an astrophysicist at Harvard. He decided to figure out the relative advantages of specific aspects of an apartment: windows, closet size, use of bathroom, etc., weighted them based on a survey of his friends, (Hmmm… perhaps not so scientific?) and generated a calculator.
This tool could be very useful in negotiating the portions of the rent each person pays. It could also be a bit TOO much. Some people like to feel their way into an equitable arrangement. Try it out, see what you think. It might just really help everyone feel that they are getting a fair deal.
Note to those already sharing: I heartily suggest that you do not try to renegotiate rents that are already set in place. That’s not fair. Choosing has to happen at the outset of the relationship.