How to Split Expenses as a Couple

The three methods, and when each one makes sense

50/50 is the simplest: each of you pays half of everything, regardless of what you earn. It works well when incomes are similar, or when the couple prefers to keep accounts completely separate and easy to calculate. The problem shows up when there's a big difference in income: half the expenses can be a much bigger slice of the lower earner's budget than the higher earner's.

The proportional-to-income method solves that: each of you contributes the same percentage of what you earn, not the same amount. If A earns twice what B does, A pays twice the expenses -- but proportionally, you're both "feeling" the same effort. It's the most commonly used method among couples with quite different incomes, for exactly this reason.

The equal-leftover method goes a step further: it doesn't just look at the income proportion, but at the absolute amount each of you has left after paying your share. It guarantees that, at the end of the month, you both have exactly the same amount of free money to spend however you like -- even if that means the higher earner pays an even bigger slice of expenses than the pure proportional split would suggest.

When incomes are very unequal

When the income gap is large, it's worth talking openly about which of the three methods feels most balanced to both of you, rather than assuming one of them is "the correct one." There's nothing wrong with revisiting the split whenever either of your financial situations change -- a promotion, a job change, or a period without income shouldn't be awkward reasons to avoid reopening the conversation.

Shared vs. personal expenses

This calculator only deals with shared expenses -- the ones that exist because you live together (rent, bills, household groceries). Personal expenses (clothing, individual nights out, your own subscriptions) usually stay outside this split, paid from what's left over to each of you after your share of the common expenses.

Joint account or not

None of the three methods requires a joint account. Many couples prefer to keep personal accounts separate and transfer each person's share into an account or shared space just for common expenses every month -- that way each of you keeps full visibility over the rest of your own money, without mixing everything together.