Income-Proportional Bill Split Calculator

About this calculator

An income-proportional split divides a shared bill so that each person pays in proportion to their own income, rather than splitting it evenly by headcount. If one partner earns 70% of a household's combined income, they pay 70% of the shared bill instead of an automatic 50%, so the expense takes up roughly the same share of each person's budget regardless of how unequal their incomes are.

The calculation is straightforward: each person's income is divided by the total combined income of everyone splitting the bill to get their percentage share, and that percentage is then applied to the total bill amount — this calculator supports up to three people splitting together.

Couples and roommates with unequal incomes commonly use proportional splitting for rent, utilities, and groceries, since a strict 50/50 split can feel disproportionately burdensome to the lower earner, while a proportional split is widely seen as a fairer way to share costs without either person tracking every individual expense.