What does this calculator do?
An equal split can feel awkward when bedrooms are very different sizes. A purely size-based split ignores equal access to kitchens and living rooms. This two-room model blends both ideas: you choose how much of the rent is shared equally and allocate the rest in proportion to bedroom area. It is a starting point for a conversation, not an objective definition of fairness.
How to use it
- Enter the total rent and measure both bedrooms in the same unit.
- Agree how much of the rent represents shared access to the home.
- Review both dollar shares together before signing an agreement.
The math, made clear
Room share = (rent × shared fraction ÷ 2) + (rent × private fraction × room area ÷ combined room area)A worked example
For $2,400 rent, 160- and 120-square-foot bedrooms, and a 50% shared portion, each room pays $600 for common space. The remaining $1,200 is split 160:120. Room A pays $1,285.71 and Room B pays $1,114.29 after cent rounding.
What to keep in mind
This model supports exactly two rooms with one payer per room. It does not price private bathrooms, couples sharing a room, parking, natural light, or noise. Agree any extra adjustments separately. It does not alter liability under a lease.
All default values are illustrative. Results are rounded for display; calculations use full precision except where a split must allocate exact cents. Read our methodology for shared definitions and report a calculation issue if a result looks wrong.