Rent split calculator: fair rent by room size

Free, no sign-up. Updated October 16, 2026

When one bedroom is bigger, an even split feels unfair to someone. Enter your rent and each bedroom's size; the kitchen, living room and bathrooms everyone uses are split evenly, and the rest of the rent follows the bedrooms.

Total monthly rent ($) Share of rent for shared space (%) 50% is a common starting point. 0% = split purely by bedroom size; 100% = split evenly.

Bedroom	Size (sq ft)	People in it

Leave a row empty to skip it. A couple sharing a room: put 2.

How the math works

Shared space. The shared percentage of the rent (kitchen, living room, hallways, shared bathrooms) is divided evenly between every person in the house, so a couple pays two shares.
Bedrooms. The rest is divided between bedrooms in proportion to their square footage. A 150 sq ft room pays 1.5 times what a 100 sq ft room pays.
Shared bedrooms. A bedroom's part is split evenly between the people sleeping in it.
Cents. Every share is rounded to the cent and the leftover cents go to the largest remainders, so the shares add up to the rent exactly.

Size isn't the only thing people price in. A private bathroom, a balcony, a parking spot or a much quieter room are worth talking about too. A simple way to account for one: agree on a dollar amount for it, subtract it from the rent before you split, and add it back to that person's share.