Splitting Your Parents' Care Costs: What's Fair?
When siblings share the cost of supporting aging parents, deciding who pays what is both a money question and an emotional one. This calculator gives you a starting point for the conversation. First, subtract your parents' own income — Social Security, pension, rental, or other sources — from their monthly expenses to find the actual shortfall siblings need to cover. Then it shows two ways to split that shortfall: an equal split, where everyone pays the same amount, and an income-proportional split, where each sibling contributes based on their share of total sibling income.
When siblings' incomes differ significantly, an equal split can feel disproportionately burdensome for the lower earner, which is why a proportional split often feels fairer. That said, non-financial contributions matter too — a sibling who lives with your parents or handles medical appointments and day-to-day caregiving is contributing real value that's hard to capture in a formula. Factoring that in when you finalize the money split can go a long way toward avoiding resentment. Treat these numbers as a starting point for discussion, not the final word.
Frequently Asked Questions
Common approaches are an equal split or an income-proportional split. When incomes differ a lot, proportional tends to feel fairer.
Subtract their Social Security, pension, or other income from expenses first. The remaining shortfall is what siblings need to cover.
Yes — caregiving and living together are real contributions that are hard to quantify but worth factoring into the financial split.
※ The right split depends on family circumstances and non-financial contributions. This is a reference estimate only.