Follow the default numbers.
With monthly rent of $2,400, the model gives monthly household total: $2,600.
The formula is room weight ÷ total weight × rent. Open the breakdown to trace expenses and assumptions. Change one input at a time to see how your decision changes. This example uses scenario inputs; it is not an offer, tax bill, appraisal or legal determination.
A fair split starts with an agreed rule
Equal-by-person splitting divides rent among occupants, including two people sharing a room. Income splitting gives each room a weight based on the income entered for that room. Enter both occupants’ combined income for a couple when using income mode. The method should be agreed before signing a lease; a mathematical allocation does not change each tenant’s obligations to the landlord.
Room size and common space
Area mode assigns each room its bedroom area plus an equal share of the shared space. This prevents a small difference in bedroom size from controlling the full apartment rent. Feature mode also adds the agreed equivalent-area weight for a private bathroom, parking or another exclusive benefit. These weights express the roommates’ preferences; they are not market valuations. Utilities are divided per person in every mode.
Keep the total exact
The breakdown rounds the final shares to cents and allocates the last rounding remainder to the last room. The rent and utility columns therefore reconcile to the amounts entered. If everyone has zero income, income weighting cannot be calculated. Use equal mode or enter actual incomes instead. You can add up to six rooms, rename each roommate and copy the complete table.
Use the breakdown as a conversation
Check whether a room’s occupant receives an exclusive benefit, whether a couple should share common costs differently and how a vacancy will be handled. A saved breakdown is useful when renewing the lease or changing utility estimates. It is not a roommate agreement. Discuss deposits, early departure, guests and responsibility for unpaid rent separately from the monthly allocation.
Keep your assumptions with the result
Save the calculation to your deal file to reuse compatible inputs in another tool. The file stays in this browser on this device. Download the CSV to open the complete inputs, results and schedule in Excel or Google Sheets. Use PDF to print the report or save it as a PDF. A share link includes entered financial figures in its URL, so use it only with people you intend to share those numbers with.