Why use this calculator
Splitting rent fairly among roommates can be a source of conflict. This calculator uses room sizes to determine each person's fair share, accounting for both private and shared spaces.
How to use it
Enter the total monthly rent, select the number of rooms, input each room's square footage, and the common area size. The calculator splits rent proportionally based on each room's size plus an equal share of common areas.
The formula
Each room's share = (Room sq ft + Common area / Number of rooms) / Total sq ft x Total rent. Common areas are divided equally among all roommates, while private room costs are proportional to size.
Worked examples
3 roommates, $2,400 rent: rooms of 150, 120, and 100 sq ft with 200 sq ft common area
Room 1 pays ~$877, Room 2 pays ~$807, Room 3 pays ~$716
2 roommates, $1,800 rent: rooms of 180 and 140 sq ft with 300 sq ft common area
Room 1 pays ~$977, Room 2 pays ~$823
When people use it
- New roommates setting up a fair rent arrangement
- Existing roommates renegotiating after a room change
- Couples sharing with singles who use different sized rooms
- Subleasing a room and determining fair pricing
Tips
- Measure rooms from wall to wall including closet space for accuracy
- Consider adjusting for amenities like an attached bathroom or better view
- Factor in common areas that everyone shares equally
Questions people ask
- What counts as common area?
- Common areas include the kitchen, living room, hallways, bathrooms shared by all, laundry area, and any other spaces used by all roommates equally.
- Should master bedrooms with bathrooms pay more?
- Yes, an attached bathroom adds significant value. You can include bathroom square footage in that room's measurement or add a percentage premium on top of the calculated share.