How to split rent when bedrooms are different sizes

In a shared apartment, the biggest bedroom often has its own bathroom, another opens onto the balcony, and the third barely fits a bed. Splitting the rent three ways still works, but someone ends up paying for another person’s comfort. The most common fix separates two things: the space each person uses alone, split by size, and the shared space, split equally.

Three methods, three ideas of fair

An equal split is the simplest. It works when the bedrooms are comparable, or when the group would rather not keep score. It becomes hard to defend once one room is clearly larger or better equipped.

Splitting by total square footage, bedrooms included, gives room size too much weight. The living room, kitchen and shared bathroom serve everyone equally. Someone in a small bedroom uses the same living room as someone in a large one.

A mixed method handles both realities separately. It works out how much of the home is private and how much is shared, then splits the first by size and the second equally. Features that square footage does not capture, such as a private bathroom or a balcony, are then handled with a small adjustment the group agrees on.

A worked example, step by step

This example is fictional. Maya, Jordan and Casey rent an 800 sq ft apartment for $1,800 a month, utilities extra. Maya’s bedroom is 160 sq ft; Jordan’s and Casey’s are 120 sq ft each. The bedrooms add up to 400 sq ft, and the shared areas to another 400 sq ft.

Step one: half the apartment is private, so half the rent is too, which is $900. The other $900 pays for the shared areas.

Step two: the $900 for shared areas is divided by three, so $300 each.

Step three: the private $900 is split by bedroom size. Maya has 160 of the 400 private sq ft, or 40%: $360. Jordan and Casey each have 120 sq ft, or 30%: $270 each.

• Maya: $300 + $360 = $660.
• Jordan: $300 + $270 = $570.
• Casey: $300 + $270 = $570.

The total is $1,800, exactly the rent. With an equal split, everyone would pay $600: Maya would pay $60 less than her calculated share for the largest room, and Jordan and Casey $30 more each.

Adjusting for a private bathroom or a balcony

Now suppose Maya’s room has its own bathroom and Jordan’s opens onto the balcony. The group agrees on a monthly value for each perk: $60 for the bathroom, $20 for the balcony. No formula produces these numbers; they are negotiated. What matters is the redistribution rule: the person with the perk pays the premium, and the other two share the same amount as a discount.

• Bathroom: Maya +$60, Jordan −$30, Casey −$30.
• Balcony: Jordan +$20, Maya −$10, Casey −$10.

Result: Maya $660 + $60 − $10 = $710, Jordan $570 − $30 + $20 = $560, Casey $570 − $30 − $10 = $530. The total is still $1,800. A well built adjustment never changes the rent, only how it is divided. If your numbers no longer add up to the rent, a premium was added without a matching discount.

When measuring rooms, use the same rule for everyone, such as wall to wall floor area, and decide upfront how to count closets or a sloped ceiling. Measuring every room the same way matters more than the exact convention.

What the split does not change for the landlord

How roommates divide the rent is an agreement among them. It does not bind the landlord. The People’s Law Library of Iowa explains that a shared lease often makes tenants jointly and severally liable: each is fully responsible for the whole rent, so if one roommate does not pay, the landlord can require the others to pay the full amount. Rules vary by state and lease, so read yours. The shares above settle accounts between you; they do not limit what the landlord can claim.

Write down the method and the amounts in a shared document or a pinned message, with the date. Also decide what happens when someone moves out: does the new roommate take the same room at the same price, or do you recalculate? A rule set at the start avoids renegotiating every time a room changes hands.

Utilities, internet and groceries often follow other rules than rent. See our guide to splitting roommate groceries and bills.

Tracking rent every month

In Spliz, a roommate group can add the rent as an expense, split it by shares or exact amounts, and check each person’s balance. It is free, and roommates join the group as guests by installing the app, without creating an account. Spliz does not pay the landlord and does not move money: repayments happen by bank transfer, in cash or with another app, and are then recorded in the group. For an overview, see the roommates page.

Spliz

Sources

• People’s Law Library of Iowa, Roommates and Co-signing a Lease, joint and several liability under a shared lease (accessed November 9, 2026).
• Spliz, available features, what the app does today.