Fair Rent Split

Split rent by room size

Enter the rent and each bedroom's size. The common areas are split per person and the bedrooms by floor area, with a bit extra for a private bathroom, balcony, walk-in closet or parking space.

Don't know the room sizes, or think size isn't the point? Use bidding instead.

Rent
Common areas and extras

The common-area share pays for the kitchen, living room and hallway, and it's split per person. I start it at 40%. Use less if the bedrooms are most of the floor plan.

Bedrooms
RoomSizePeopleOwn bathBalconyWalk-inParkingRemove

What each room pays

RoomPaysEach personShare
Total

Compared with other ways to split

Most arguments are about the method, so here are the same rooms split three ways.

RoomEqual per personBy size onlyThis page

"By size only" ignores the common areas and extras, so a couple pays the same as one person in a room that size.

How it's calculated

room pays = common × (people in room ÷ all people) + bedrooms × (room's adjusted size ÷ all adjusted sizes) adjusted size = size × (1 + bathroom % + extras % for each of balcony, walk-in, parking)

Rounding is to the cent, and any leftover cents go to the rooms with the largest remainders, so the total always matches the rent exactly.

This is arithmetic, not advice. It won't know that the front room gets the street noise or that someone works from home. Adjust the percentages until it matches what your group thinks is fair, or use bidding, which takes those things into account by asking people directly.

Questions

How do you split rent when bedrooms are different sizes?

Split the common areas evenly per person and the bedrooms by floor area. Measure each bedroom wall to wall, multiply length by width, and enter it above. Everyone has to use the same unit.

Should a couple pay more rent?

Here a couple pays for one bedroom but two shares of the common areas, because two people use the kitchen, bathroom and utilities. Set the common-area share to 0% if your group thinks a couple should pay the same as one person.

How much extra for a private bathroom?

I treat it as making the room 15% bigger. Change it if you disagree. In places where shared bathrooms are normal, I've seen groups go up to 25 or 30%.

What if we can't agree on what the rooms are worth?

Try bidding. Everyone says what each room is worth to them, and it finds who should get which room and prices where nobody would rather swap.

Someone is moving in halfway through the month. What do they owe?

That's the partial month calculator. It shows the three common ways landlords and roommates prorate, since they give slightly different answers.