How should couples with very unequal incomes think about fairness in their budget?

Shift the mindset from splitting costs equally to funding a shared life fairly. When incomes differ a lot, contributing the same percentage of each income toward joint expenses and savings usually feels fairer than a strict dollar split, because it leaves both partners with comparable breathing room. Beyond the mechanics, treat the household's money as a team resource working toward shared goals rather than tallying who paid for what. Give each partner some independent spending money so neither feels controlled. Discuss and agree on the approach openly, and revisit it whenever incomes change, such as after a raise, a job change, or one partner scaling back for caregiving. The specific formula matters less than both people feeling the arrangement is respectful and transparent.