How to split groceries and bills with roommates

To split groceries with roommates, remove personal purchases from the receipt first. Divide each shared purchase among the people it covers, then subtract what each person already paid. Splitting the supermarket total equally works only when the entire basket belongs to everyone.

One receipt might contain dish soap, dinner for two and one person’s breakfast. There is one payer, but different people owe a share. Three separate entries keep that distinction visible.

Agree on what belongs in the household budget

• For the home: cleaning supplies, internet or an energy bill, depending on your agreement and contracts.
• For some roommates: a meal, drinks or a purchase used by only part of the household.
• For one person: their own food, toiletries or subscriptions, kept outside the shared account.

Write down which basics you buy together, the budget and when a purchase needs approval. France’s official Service Public guide describes a household agreement that can list shared expenses and their allocation. This is a French reference, not a universal tenancy rule. Check your own lease and local requirements separately.

Three roommates, $180 shared and two repayments

Fictional example: Alex, Maya and Sam split household basics equally. Alex pays $120 for shared groceries. Maya pays $42 for dinner with Alex. Sam buys $18 of cleaning supplies for everyone. Alex’s $24 of personal purchases stays outside the calculation.

Alex and Maya each owe 40 + 21 + 6 = $67 of the expenses. Sam’s share is 40 + 6 = $46. That accounts for all $180. Now compare each share with the amount already paid:

• Alex paid $120 against a $67 share: Alex receives $53.
• Maya paid $42 against a $67 share: Maya sends Alex $25.
• Sam paid $18 against a $46 share: Sam sends Alex $28.

The $25 and $28 cover Alex’s $53. Asking Maya for another $67 would ignore the dinner she paid for. Enter these three purchases in the shared-expense repayment calculator, leaving Sam out of dinner.

A week away does not remove every bill

Treat meals separately from costs that continue during an absence. You might exclude a roommate from dinners they miss while keeping their agreed internet share. Nights at home alone do not measure someone’s electricity use.

For energy, check the billing period, fixed charges and billed consumption before choosing a split. Do not add utilities again if they are already included in the amount paid to the landlord. Moving out also requires checking the lease and supplier contracts. This guide organizes household accounts; it does not decide what a landlord or supplier can claim.

A message to agree on before shopping

Adapt it to the household. Someone who rarely eats at home may prefer to buy their food separately. Sharing an apartment does not require sharing the entire fridge.

Keep purchases and advances together

In your Spliz roommate group, add each expense with its payer and participants. Separate a mixed receipt according to your agreement. Keep the rent allocation you chose instead of automatically applying the grocery split to it.

Repay with your usual payment method, check receipt of the money, then record it in the app. Recording a repayment does not move money. At the next review, the group can focus on what remains instead of asking for an amount already received.

Sources and method

• Service Public, French shared-tenancy rules and household agreements, checked October 24, 2026.
• Spliz feature availability, expense tracking and repayments made elsewhere.
• Original example and calculations. Fictional amounts and an agreed split chosen for this example.