Splitting costs

Splitting costs with a partner sounds simple until the real bills arrive: rent, the weekly grocery run, the energy bill that lands while one of you is away. This section collects the methods couples actually use, with the numbers next to them.

It starts with the usual question: fifty-fifty, or in proportion to income? Take incomes of $4,000 and $3,000 a month and $2,800 of shared costs. Split evenly, each of you pays $1,400; split by income, one pays $1,600 and the other $1,200. Neither is right for everyone, and the articles explain when each one works better.

You'll also find how to set things up when you move in together, how to keep track without a spreadsheet, and what to do with costs that belong to neither of you, like a gift for a mutual friend. If you want your own numbers right now, try the free calculator.