Roommate Rent Split Calculator

Splits a shared rent four ways: equally, by room size, by room size adjusted for private baths and shared space, and by income.

Shows each person's difference from an equal split and share of income.

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Results will appear here once you enter your values.

Four ways to divide the rent

Enter the total monthly rent, the shared space in square feet, a private-bath premium, and a row for each roommate with room size, private bath yes or no, and optional monthly income. The tool then shows four splits side by side.

  • Equal: total rent divided by the number of people.
  • Room size: each person's share of the combined room area.
  • Adjusted: room area, raised by the bath premium for private baths, plus an equal share of shared space, then pro-rated.
  • Income: each person's share of combined income.

For every method, each person's card shows the dollar amount, the difference from the equal split, and the share as a percent of income when income is entered.

Limits of the numbers

The bath premium and the way shared space is counted are choices, not rules. Changing the premium from 10% to 20% moves money between people, and two reasonable groups can land on different answers. Use the tool to make the trade-offs visible, then agree on a method together.

The income split treats rent as proportional to income, which can put a large burden on the higher earner and ignores savings, debts and who uses which spaces. The 30% flag is a screening rule of thumb based on HUD's cost-burden definition, not a judgment about what anyone can afford. This tool is not legal advice and does not change what each tenant owes the landlord under the lease.

Sources and a worked example

Default example: $3,000 rent, rooms of 160, 130 and 110 sq ft, 400 sq ft shared, 10% bath premium on the 160 sq ft room, incomes of $5,000, $4,000 and $3,000. Equal is $1,000 each. Room size gives $1,200, $975 and $825. Adjusted gives about $1,137.25, $968.14 and $894.61. Income gives $1,250, $1,000 and $750. The first person's $1,250 income share is 25% of a $5,000 income, and the third person's $825 room-size share is 27.5% of $3,000.

  • Pro-rata area allocation: University of California San Francisco Controller's Office, cost allocation methodology best practices (worked example 1,600 / 2,800 x $3,000).
  • Income-proportional split: Divvy, "How to Calculate Rent" (example $3,000 / $8,000 x $2,400 = $900).
  • 30% cost-burden threshold: U.S. Department of Housing and Urban Development, HUD User, rent burden in the Housing Choice Voucher program.

Frequently Asked Questions

Common questions about the Roommate Rent Split Calculator

Each person pays total rent times their room's square feet divided by the combined square feet of all rooms. With $3,000 rent and rooms of 160, 130 and 110 sq ft (400 total), the shares are $1,200, $975 and $825. Shared space is ignored in this method. Amounts are allocated in whole cents so the shares always add up exactly to the rent.

Sources & References

Mortgages and home-buying

Consumer guidance on mortgages, closing costs, and home financing.
→Source: Consumer Financial Protection Bureau (CFPB)

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