How to Split Bills and Expenses With Roommates

Split each shared bill by one rule that every roommate agrees to in writing: equal shares per person, the same percentages you use for rent, or a usage-based split when one roommate clearly uses more, for example by running a space heater all winter. The roommate whose name is on each account should collect the other shares a few days before the bill is due, through a payment method that leaves a record. Keep groceries and personal items separate unless you regularly cook together, and cover household basics such as toilet paper and dish soap from a small shared fund.

Which costs to split

Start with the lease, which says which utilities the tenants pay and which the landlord covers. Then list every shared cost and who manages it:

• Utilities: electricity, gas, water, sewer, and trash, if the lease puts them on the tenants.
• Internet and streaming services everyone uses. If the internet plan has a contract, agree in writing who pays any early termination fee and who keeps the equipment if the household breaks up.
• Household supplies used in shared spaces.
• Shared groceries, if you buy any.
• Furniture or appliances for common areas. Decide who owns each item, and whether it is sold or bought out, when someone moves.

California's Department of Real Estate tenant guide recommends that a written sublease say who pays the gas, electric, water, trash, and telephone bills, and the same list belongs in any roommate agreement. Rent is divided separately; see how to split rent fairly with roommates.

Which split method should you use?

Pick one method for each bill and write it into your roommate agreement. The method can differ by bill, for example internet split equally and electricity by usage.

Worked example

Ana, Ben, and Cal share these monthly bills: electricity $150, gas $45, water, sewer, and trash $85, and internet $70, for a total of $350. Ana has the largest room and pays 40% of the rent; Ben and Cal pay 30% each. Ben runs a 1,500-watt space heater in his room about 6 hours a day.

To price the heater, use the formula the U.S. Energy Information Administration (EIA) gives: watts times hours of use, divided by 1,000, equals kilowatt-hours (kWh). Over a 30-day month, 1,500 watts times 6 hours times 30 days, divided by 1,000, is 270 kWh. The EIA reports a U.S. average residential price of 18.31 cents per kWh for July 2026, so the heater adds about $49.44 a month (270 times $0.1831). Use the rate on your own bill, because prices vary by state and month.

In the usage-based row, $350 minus $49.44 leaves $300.56. Ana and Cal pay $100.19 each, and Ben pays the remaining $100.18 plus the $49.44 for the heater.

If Cal's partner moves in and the household counts each partner as a resident, the equal split becomes $87.50 per person ($350 divided by 4), so Cal and his partner pay $175 together.

How to track and collect payments

1. Assign each account. Put each utility in one roommate's name and record who holds which. That person owes the provider the bill and collects from the others; see whose name utilities should be in.
2. Set a roommate due date. Make shares due at least 5 days before the provider's due date.
3. Post every bill. Share a copy of each bill and the math in a group chat or shared spreadsheet the day it arrives.
4. Pay with a record. Use bank transfers, checks, or a payment app rather than cash. TexasLawHelp.org notes that emails, bank statements, and canceled checks can prove what each roommate contributed, and the Consumer Financial Protection Bureau (CFPB) advises using payment apps only with people you know and trust. Our guide to rent payment apps for tenants compares the apps.
5. Prorate move-ins and move-outs by day if agreed. If all roommates agree to charge only for days of occupancy, a roommate who moves out 10 days into a 30-day billing period owes one third of their usual share: $116.67 times 10/30 is $38.89. An account holder can still owe the utility provider for charges after moving out until service is canceled or transferred.
6. Follow up on a missed share in writing. State the amount, the bill it covers, and a date to pay. Michigan Legal Help says you can usually sue a roommate who does not pay a share you covered, and small claims courts hear these cases up to a set limit, such as $12,500 for an individual in California and $20,000 in Texas justice court. See what to do when your roommate won't pay rent for the steps before court.

Groceries and household supplies: shared or separate?

Everyone uses the household supplies, so pay for them from a shared fund:

• List what it covers: toilet paper, paper towels, dish soap, trash bags, cleaning products, and light bulbs.
• Set a monthly amount, such as $20 per person, held by one roommate or tracked in a shared spreadsheet with receipts.
• Settle at the end of each month, so whoever spent more is repaid.

Groceries take more agreement. Keep food separate when your diets, budgets, or schedules differ, when one roommate has a partner who eats there often, or when someone has a food allergy. Give each person a shelf in the refrigerator and pantry, and set a borrowing rule, such as asking first and replacing the item within a week.

Sharing groceries works when you cook together most nights. Split each receipt equally or by the number of meals each person ate, and buy personal items, such as snacks, coffee, or alcohol, on separate receipts.