How to split rent when the bedrooms are different sizes

An equal split is the easiest math and the easiest argument. Three people, one rent, divide by three. It works when the bedrooms are close to the same. It stops working the day one roommate has the big room with the window seat and another has a room that barely fits a desk.

The fix is not to haggle over every square foot. Split the rent in two layers: one share for the parts of the home everyone uses equally, and one share for the bedrooms, priced by size and features. Then test the result and write it down. The rest of this guide walks through that, with numbers you can swap for your own.

One scope note: this is about dividing the money among roommates. What your lease says about who owes the landlord is a separate question, covered near the end.

Start with the total monthly rent on the lease, then work in four steps. Do them on paper or in a shared note before anyone signs.

Pick the split between the two layers first. Half and half is a good starting point: half of the rent covers the kitchen, living room, hallways and any shared bathroom, which everyone uses the same, and half is the bedroom pool. If your common space is a tiny galley kitchen and a closet of a living room, move more weight to the bedrooms. If the common space is the best part of the place, move more weight to it. Agree on the number out loud.

Here is a worked example. A three bedroom in Ann Arbor has a median asking rent of $3,000 a month across 24 active listings, per Wroomly's live rent prices guide (https://wroomly.app/guides/ann-arbor-rent-prices), computed 2026-11-03. That is a market median, not your rent, so use it only to follow the math and swap in the number from your own lease.

The bedroom sizes below (150, 120 and 110 square feet) are made up for the example. They are blanks for you to fill in with your own measurements. The split is half common space, half bedrooms: $1,500 shared three ways is $500 each, and the other $1,500 is divided by bedroom size.

Fill in the same columns with your own numbers: bedroom size, that room's share of the bedroom total, its piece of the bedroom pool, the equal common space share, and the monthly total.

Square footage does not capture everything. A room with its own bathroom, a walk in closet, a balcony door or a spot in the driveway is worth more than the same size room without them. A room with no window, or one you walk through to get to another room, is worth less.

Handle these as a flat dollar adjustment you agree on, not a new formula. Add or subtract it after the bedroom math, then spread the opposite amount across the other roommates so the total still matches the rent. A parking spot is the simplest case: if only one person uses it, that person pays for it.

Pick adjustments you could explain to a stranger by looking at the room. Features of the room and the lease, never anything about the person who takes it.

Numbers can be correct and still feel wrong. Run one test before you lock it in:

Would you swap bedrooms with either roommate at the price they would pay for it? If everyone says no, the split holds. If someone says yes, that room is priced too low or yours is priced too high, so move a few dollars and ask again.

Decide who picks rooms before you see the prices: lowest price first, a draw, or the order people joined the lease. Rooms get assigned by that agreed rule, so nobody has to defend why one person got the big one.

Write the split down the day you agree, with the date and everyone's initials or a reply of agreed in a shared chat. A one page note is enough: the total rent, the percentage or dollar amount for each person, the adjustments, who pays the landlord, and what happens if someone is late.

The university's off campus living guide, which is published by the university and separate from Wroomly, suggests deciding early how costs will be split and how and when payments are made. It also suggests keeping records of who pays what, especially when an account is in one person's name. Do both.

For utilities, the simple default is an equal split, because the kitchen, the lights and the heat in the common rooms serve everyone. If one person works from home all day or runs a space heater, talk about it before the first bill, not after. Whoever holds the account fronts the money, and everyone else pays them back by a set day each month.

Nothing in your split changes what the landlord can ask for. Some Ann Arbor leases are joint and several, which commonly means each tenant can be held responsible for the full rent and not just their share. The university's off campus guide describes this, and Michigan Legal Help says that when roommates are all on a lease, a private agreement to split the rent does not limit what the landlord can demand from each of them.

So treat your split as a deal among friends that the lease sits on top of. Before you sign, ask the landlord how a roommate can leave or be replaced, and what approval and paperwork that takes. If a roommate stops paying, read your lease first, then talk to your landlord, the university's Student Legal Services if you are a student there, or a lawyer. This guide cannot tell you what your lease means or what you are owed.

In your written split, add one line for this case: how much notice a leaving roommate gives, who finds the replacement, and who covers the share in the gap.

Measure the rooms this week, run the four steps, and send the table to your roommates before anyone puts a name on a lease. If you are still comparing places, you can compare current shared places on Wroomly and run the same math on any three bedroom you like.