Each partner's share
A pays
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B pays
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A keeps
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B keeps
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Split of shared costs
All three methods
| Method | A pays | B pays | % of income (A / B) |
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This is an educational calculator only. It is not financial, tax, or relationship advice, and it does not say which split is right for you. Numbers stay in your browser.
How the three methods compare
50/50. Each partner pays half. It is easy to explain and to track, and it suits couples with similar incomes. When incomes differ a lot, the lower earner spends a much bigger share of their pay on the household.
By income. Each partner pays the same percentage of their own income. With incomes of 4,000 and 2,500, the first partner earns about 61.5% of the total and covers about 61.5% of shared costs. On 2,600 of shared costs that is 1,600 and 1,000, or 40% of each income.
Custom %. You agree on your own number, for example 60/40, or a split that accounts for unpaid work, childcare, or debt one partner brings in.
Settling up. If you pay shared bills from separate accounts, add up what each of you actually paid, apply your split to that total, and transfer the difference once a month.
Questions
What is a fair way for a couple to split bills?
There is no single right answer. A 50/50 split is simple and works well when incomes are similar. A split in proportion to income asks each partner to put the same percentage of their income toward shared costs, which many couples find fairer when one earns noticeably more. Some couples pick their own percentage. The best split is the one you both agree on and review when incomes change.
How does splitting bills by income work?
Add both after-tax incomes and work out each partner's share of the total. If one partner earns 4,000 and the other 2,000 a month, the first earns two thirds of the household income and covers two thirds of shared costs. With 2,400 of shared costs that is 1,600 and 800, which is 40% of each person's income.
How do we settle up at the end of the month?
Add up what each partner actually paid toward shared costs, work out each partner's fair share of that total, and compare. The partner who paid more than their share is owed the difference, and one transfer of that amount evens things out.
Should we use a joint account?
Some couples pay every shared bill from a joint account and each transfer their share into it on payday. Others keep separate accounts and settle up monthly. Both work. The calculator gives the monthly amount each partner would transfer to a joint account, or the settle-up amount if you pay from separate accounts.
Are my numbers saved or sent anywhere?
No. The calculator runs entirely in your browser. Nothing you type is stored or sent to a server.
Want this every month, in a spreadsheet?
The Wellkept Couples & Paycheck Budget keeps a running shared-bills log with a who-owes-whom balance, plans which paycheck covers each bill, and adds sinking funds and a snowball or avalanche debt payoff plan. Excel and Google Sheets, English and German. Files stay with you.
See the Couples & Paycheck Budgetor start with the free Life Admin Starter