Free calculator
How should we split the shared bills?
For couples and flatmates. Add your two incomes and the monthly costs you share, and compare half and half with a split by income.
After tax: what lands in your account each month.
Your split
Shared costs: €1,500.00 a month.
| Half and half | By income | |
|---|---|---|
| You | ||
| Pays | €750.00 | €900.00 |
| Of income | 31.3% | 37.5% |
| Left over | €1,650.00 | €1,500.00 |
| Partner | ||
| Pays | €750.00 | €600.00 |
| Of income | 46.9% | 37.5% |
| Left over | €850.00 | €1,000.00 |
Half and half tends to feel fair when you earn about the same, or when keeping it simple matters most. By income tends to feel fair when your incomes are far apart, because each of you puts in the same share of what you earn.
Your split Shared costs: €1,500.00 a month. You Half and half: €750.00, 31.3% By income: €900.00, 37.5% Partner Half and half: €750.00, 46.9% By income: €600.00, 37.5%
Nothing you type leaves your browser. The sums are done on this page, and nothing is saved or sent anywhere.
How the two splits are worked out
half and half: each pays costs ÷ 2 · by income: your share = costs × your income ÷ (your income + their income)
On half and half, an odd cent goes to the first person. For each person the calculator then shows the amount, what percentage of their own income it is, and what is left of their income after paying it.
On a split by income, whoever earns more pays more money but the same percentage of their income as the other person. That percentage is the shared costs divided by the two incomes together.
A worked example
You earn €2,400 a month and your partner earns €1,600. You share rent of €900, utilities of €150 and groceries of €450: €1,500 in all.
Half and half: €750 each. That is 31.3% of your income and 46.9% of your partner’s, leaving €1,650 and €850. By income: you bring in 60% of the €4,000 you earn together, so you pay 60% of €1,500, which is €900, and your partner pays €600. That is 37.5% of each income, leaving €1,500 and €1,000. These are the amounts the calculator opens with.
Which split is fairer?
Neither is right in itself. Half and half is simple, and feels fair when you earn about the same. By income asks the same share of each of you, and tends to feel fair when one of you earns much more. Some pairs choose something in between, or split rent one way and groceries another.
Does this work for flatmates?
Yes. Two flatmates can use it exactly like a couple, each entering their own income. For more than two people, half and half is simply the costs divided by the number of people; this calculator handles two.
What if one of us has no income?
Half and half still divides evenly, which may not be workable for the person with no income. By income, that person pays nothing and the other pays everything. Neither is a verdict: it’s why many pairs talk it through and settle on a figure in between.
General information, not financial advice. Your own situation may call for different numbers.
Keep the shared budget in one place
In Spentalot you can invite your partner into a budget, so you both log into the same month and see the same bills. Sharing a budget is part of Pro and Family, and the person you invite joins free on any plan. No bank login.
Free forever plan · 14 days of Pro, no card