proportional split

Also called: split in proportion to income

Sharing a couple's common costs so that each partner pays the same percentage of their own income.

In a proportional split, each partner's share of common costs equals their share of the couple's income: common costs × (your income ÷ both incomes). Both then hand over the same percentage of what they earn.

It solves the problem of a 50/50 split when incomes differ: equal amounts take a bigger bite from the smaller salary and can even exceed it. Proportional shares keep the effort equal, though the personal money left to each still differs in hryvnias.

It's one of three common setups, next to everything joint with equal personal money and fully separate money with bills divided. None is right for everyone; the one both partners understand and find fair is the one that works. Review it when an income changes.

Example

Sam earns 31,000 UAH and his wife 25,000; common costs are 53,000 a month.

Split	Sam pays	Wife pays	Left to Sam	Left to wife
50/50	26,500	26,500	4,500	−1,500
Proportional (55.36% / 44.64%)	29,339.29	23,660.71	1,660.71	1,339.29

Common mistakes

Assuming 50/50 is fair by default. With different incomes it can leave one partner below zero.
Forgetting unpaid work. Childcare or a parental leave changes what “fair” means.
Never revisiting it. Shares change when incomes do.

Learn it in the course

Money and a partner: joint, separate or both · Splitting shared costs fairly when incomes differ, and a few rules that stop money fights before they start.