Split bills by income. Decide together.

How an income-based bill split works

Use each person's take-home income for the same month and currency. Add those amounts, then divide each person's income by the household total. Multiply that fraction by the shared bill.

Your share = your take-home income ÷ household take-home income
Your contribution = your share × shared costs

This gives each person the same percentage of income devoted to those shared costs. It can be a useful starting point for a couple with different paychecks. You still decide which bills are shared and whether the resulting amounts work for both of you.

Example: $4,000 and $2,000 take-home pay

Alex takes home $4,000 a month and Jordan takes home $2,000. Their shared rent and household bills total $1,800. These are illustrative amounts.

With an equal split, Alex puts 22.5% of take-home pay toward the bills and Jordan puts 45%. With the income-based split, each puts 30% toward those same costs.

The exact ratio is 2 : 1. The displayed percentages, about 66.67% and 33.33%, are rounded. Using ratio weights avoids turning that agreement into a rounded 67/33 split.

Choose what belongs in your shared budget

Start with the expenses you both agree to share, such as rent, groceries, or utilities. Keep personal purchases out of that total unless you have agreed otherwise. Use a consistent period so you are comparing monthly costs with monthly income.

If incomes vary, you can agree on an average over a period you both consider representative and revisit it regularly. The calculator uses the numbers you enter; it does not forecast earnings.

When a custom split makes more sense

Income does not capture caregiving, debt commitments, disability-related costs, or other responsibilities. You may decide on 60/40, equal contributions for some expenses, or a different agreed ratio. An income-based suggestion is optional.

If one person has no take-home income, a strictly proportional formula assigns that person a zero contribution. If both incomes are zero, the formula cannot produce a split. Agree on a custom arrangement that fits your circumstances instead.

Use your agreement for everyday bills

1. Try equal, income-based, and custom shares in the free calculator.
2. Copy the split and manually enter the app-ready weights in FairTally's Default Split Settings.
3. Record shared expenses and who paid. FairTally applies the saved default, with an option to change the split for an individual expense.
4. Check balances together and record settlements after arranging payment.

Who pays upfront can change from bill to bill. If Alex pays all $1,800 in the example above, Jordan owes Alex $600. If Jordan has already paid some shared bills, those payments count toward Jordan's share too.

Read the step-by-step guide to saved splits and balances for the exact controls and examples. The saved ratio handles allocation; you still record each expense.

Try the numbers without an account

The free calculator runs in your browser. It does not send entered incomes to a server or save them in browser storage. Copying a result puts it on your clipboard only when you select Copy split.

The FairTally app is separate: it uses an account to keep a shared household expense record. No bank linking is required. You can enter an agreed ratio without entering incomes into the app.

Sharing bills with more than two people? See the guide for throuples and polycules for a three-person example with different payers.