What is the fairest way to split bills?

There is no single answer. Splitting by income means each person pays the same share of what they earn. An equal-leftover split means each person ends the month with the same spending money. 50/50 is simplest but can strain the lower earner.

Should we use income before or after tax?

After tax, ideally. It is what each person actually has to spend. Use the same basis for both of you.

Are my numbers stored?

No. The calculator runs entirely in your browser and nothing you type is sent to us.

Split bills by income calculator for couples

When you earn different amounts, 50/50 is only one kind of fair. Enter your incomes and shared costs and compare three common ways to split them.

How the calculator works

Enter what each of you takes home in a month, after tax, and the costs you share. The calculator shows three ways of splitting them, each with what you both pay and what you both have left. Everything runs in your browser and nothing you type is sent to us.

Three kinds of fair

50/50. Each of you pays half. It is the simplest and feels equal, but when one of you earns much more, the other can end up with very little of their own money each month.

In proportion to income. If one of you earns 60% of what you bring in together, they pay 60% of the shared costs. Each of you gives up the same share of your pay, which is why many couples settle here.

Equal money left over. Each of you finishes the month with the same amount to spend on yourself. It treats the household as one budget, and it is the closest of the three to fully pooling your money.

None of these is the right answer. They are different ideas of fairness, and the useful conversation is about which one you each believe in, and why.

Things to agree before you pick

What counts as shared. Rent and bills, clearly. Groceries, usually. Holidays, meals out, the car, gifts for each other's families: decide together.
How savings fit. Some couples put a percentage of each income towards joint savings before splitting anything else.
When to review it. A new job, a pay cut, parental leave or one of you studying can change which split feels fair. Agree to look again when something changes.
Unpaid work. If one of you earns less because they do more of the childcare or housework, that is a contribution too. The chore split check is a good way to see it.

If money is a sore point more generally, the money compatibility check shows where your attitudes to saving, spending and sharing differ.

Split bills by income: three fair ways, side by side