Use this before signing a lease or roommate agreement. The calculator separates base rent from shared monthly costs and upfront cash so everyone can see the tradeoff before money is due.
Household Costs
0% ignores income. 100% allocates rent by income share.
Upfront Move-in Costs
Use 1 for first month, 2 for first and last.
Roommates
Private-space values can be square feet, points, or any relative value. Use higher values for a larger room, private bath, better light, or exclusive storage.
Roommate Split Estimate
Private-space split
Per-roommate Breakdown
| Roommate | Equal rent | Private-space rent | Income-aware rent | Utilities & fees | All-in monthly | Upfront cash |
|---|
Cost Pool
| Item | Total | Allocation note |
|---|
Methodology
Equal rent divides total base rent by the roommate count. The private-space rent split allocates base rent by each roommate's private-space value divided by the household total of those values.
The income-aware rent split blends private-space rent with income-share rent. For example, a 25% income-aware blend uses 75% private-space allocation and 25% income allocation. If incomes are missing or all zero, the income portion falls back to equal shares.
Utilities, internet, parking, pet fees, and shared subscriptions are grouped as monthly shared costs. They are split equally by default, or by the selected adjusted rent share if you choose that mode. Security deposit and upfront rent follow the income-aware rent share because that is the selected monthly recommendation; move-in fees are split equally.
Important caveats
- A roommate split is a private household agreement, not a change to the lease. If the lease has joint-and-several liability, each signer may be responsible for the full rent, damages, late fees, or unpaid utilities if someone else does not pay.
- Put the split, due dates, utility reimbursement rules, move-out notice, guest rules, pets, parking, chores, and deposit-return process in a written roommate agreement before signing.
- If utilities, internet, or subscriptions are in one person's name, that person may carry credit risk and service-disconnection risk. Decide how reimbursements, late payments, and account transfers work.
- Security deposit refunds can be reduced by damage, unpaid rent, cleaning charges, missing keys, pet damage, or local lease charges. Keep move-in photos and receipts showing each roommate's contribution.
- Local laws, occupancy rules, subletting rules, rent-control rules, deposit caps, and landlord approval requirements vary. Check current local rules and the written lease.
Related calculators
Frequently asked questions
Should rent be split equally if bedrooms are different sizes?
Equal splits are simple, but a private-space split is often fairer when one roommate has a larger bedroom, private bathroom, better closet, parking access, or other exclusive benefit.
How do income-aware roommate splits work?
An income-aware split shifts part of rent toward each roommate's income share. It can make sense when roommates jointly choose a place around different budgets, but it should be voluntary and written down.
Who should pay utilities in a roommate house?
Utilities are commonly split equally, then reimbursed to the account holder. If one person uses much more power, works from home, has a pet, or uses exclusive parking, the household can agree to a different rule.
How should deposits be returned?
Record who paid each deposit and decide whether refunds follow original contributions, rent shares, or responsibility for deductions. The lease and local rules control landlord obligations.