The two methods, worked through
Take a couple with two thousand four hundred euros a month of shared costs: rent, utilities, groceries, transport, the shared subscriptions. One earns €2,400 net, the other €4,600. Combined, €7,000.
Even split
Each pays €1,200.
| Earns | Pays | Left over | |
|---|---|---|---|
| Partner A | €2,400 | €1,200 | €1,200 |
| Partner B | €4,600 | €1,200 | €3,400 |
Same contribution. Partner B ends the month with nearly three times the freedom Partner A has. That gap is where "we split everything equally" quietly stops feeling equal, because A is turning down dinners B considers unremarkable.
Proportional split
Shared costs are €2,400 of €7,000 combined income, so about 34%. Each partner contributes 34% of their own income.
| Earns | Pays (34%) | Left over | |
|---|---|---|---|
| Partner A | €2,400 | €823 | €1,577 |
| Partner B | €4,600 | €1,577 | €3,023 |
Same proportion. Both now have far more comparable spending money, though B still has roughly twice as much. Proportional splitting narrows the gap; it does not close it.
The formula, if you want it: your contribution is your income divided by combined income, multiplied by total shared costs.
Try it with your own numbers
Put your own figures in. The row that matters is not what each of you pays, it is what each of you has left.
| Method | You pay | You keep | Partner pays | Partner keeps |
|---|---|---|---|---|
| Even split | €1,200 | €1,200 | €1,200 | €3,400 |
| Proportional | €823 | €1,577 | €1,577 | €3,023 |
Share of combined income: 34%
Enter an income for at least one of you to see the proportional split.
So which one is fair?
Both, depending on what you think you are being fair about.
Even splitting treats you as two independent people sharing costs. It is transparent, it needs no disclosure of what either of you earns, and it is simple to unwind. It tends to feel fairest to the higher earner, and to couples earlier on who are not yet merging their lives.
Proportional splitting treats you as one household with two income streams. It equalises the impact of shared costs rather than the amount. It tends to feel fairest to the lower earner, and to couples with a longer horizon, especially where one partner earning less reflects a choice the two of you made together, like a career change or taking on more at home.
The trap is neither method. The trap is drifting into an even split because it required no conversation, and then one partner slowly accumulating a resentment they feel unreasonable saying out loud. An explicit even split is fine. An unexamined one is where the trouble lives.
Three questions that actually decide it
1. At the end of the month, does one of you have to think much harder about a €40 dinner than the other? If yes, you have an even split and unequal incomes, and it will surface eventually, usually as an argument about something else entirely. This is the most diagnostic question here.
2. Are you both comfortable saying what you earn? Proportional splitting requires it. Some couples are not there yet, and that is a legitimate reason to stay with an even split rather than a shortcoming. Do not let a method force a disclosure neither of you wanted.
3. Is the income gap temporary or structural? A gap that closes when one of you finishes studying is different from one that reflects two different career paths. Temporary gaps often suit a temporary proportional arrangement with an agreed review date, which is much easier to propose than a permanent renegotiation.
Puchi is a couples budgeting app built around a single weekly money date, so the split you agree stays visible to both of you instead of living in one person's head. See how it works
The variations worth knowing
- Proportional with a floor. Both contribute proportionally, but neither drops below a minimum. Often used when one partner earns very little and the other does not want the arrangement to feel like being kept.
- Even on essentials, proportional on lifestyle. Rent and utilities down the middle; holidays, restaurants and the nicer flat in proportion. Useful when one partner is driving the higher standard of living.
- Income after individual debt. Calculate proportions on income after each person's own debt payments, so the partner carrying student loans is not contributing proportionally on money already committed. Fairer, and slightly more admin.
- One partner earns nothing. Proportional arithmetic stops working at zero. Couples in this position generally treat all income as household income and give both partners an equal, unquestioned personal amount, because the alternative, where one adult asks another for spending money, corrodes things quickly.
Whichever you choose, do these two things
Agree what counts as shared. Rent and electricity, obviously. Groceries? Dinner, just the two of you? A present for their mother? The method matters far less than the list, and you will disagree on the list. Write it down.
Give both of you an unquestioned personal amount. Out of whatever is left after shared costs, carve out a slice each that never gets itemised or explained. This is not a nice-to-have. Couples with no legitimate private spending tend to develop an illegitimate version instead, and the second kind does real damage. Guilt-free personal money is the cheapest insurance in household budgeting.
Then put the review on a schedule: a short, unremarkable conversation on a fixed day rather than one triggered by a card being declined.
