Co-KidsExpense split calculator
One expense for the kids, two parents: who pays how much? Enter the amount, pick the rule — 50/50 or in proportion to income — and get each parent's share, with a ready-to-send message.
Your numbers never leave your browser: everything is calculated right here, nothing is sent or stored.
Enter an amount to see each parent's share.
Both rules, side by side
| Rule | Parent A | Parent B |
|---|---|---|
| 50/50 | — | — |
| In proportion to income | — | — |
What about the whole month's expenses?
Every expense of the month, tallied automatically from your WhatsApp conversation: that's the Co-Kids app, free. Live balance, monthly report, custody calendar.
Download Co-Kids for freeFrequently asked questions
Are my amounts and incomes sent anywhere?
No. Everything is calculated in your browser, on your device. No data is sent to any server and nothing is stored: close the page and nothing remains.
Should we split expenses 50/50 or in proportion to income?
A 50/50 split is simple and works well when incomes are similar. An income-based split often feels fairer when they differ: each parent contributes according to their means. What matters most is agreeing on one rule together and sticking to it.
How is the income-based split calculated?
Add both parents' net incomes, then each parent pays the fraction matching their share of the total. Example: incomes of €2,400 and €1,600, i.e. 60% and 40% — for a €100 expense, one parent pays €60 and the other €40.
Is this calculation legally binding?
No, it is an information tool designed to help parents reach an agreement. If you disagree, or to set an official child maintenance amount, speak to a family mediator, a lawyer or your local family court.
This tool reflects its author's views only and does not constitute legal advice. For your personal situation, consult a professional (lawyer, family mediator, notary) or the official services of your country. Your numbers never leave your browser.