Why the big headline number does not help you
Every year a study puts a total on raising a child to eighteen. The figure makes headlines and helps nobody: it averages across countries with completely different childcare systems, across income levels, across parents who moved to a bigger flat and parents who did not. It also arrives as one giant sum, which is the least useful shape for a decision you make one month at a time.
Break it into three layers instead. They behave differently, arrive at different times, and only one of them dominates the arithmetic.
Layer 1: the setup cost
Everything you buy once. A cot, a pram, a car seat, the furniture, the initial wardrobe, possibly a bigger car or a deposit on a larger flat.
It is real, it lands fast, and it is the layer people plan for — which is exactly why it rarely causes the damage. It is also the most compressible: second-hand markets for baby equipment are enormous, and almost none of it is used long enough to wear out. Treat this layer as a one-off savings goal with a deadline you already know.
Layer 2: the recurring monthly cost
Food, clothing, nappies, healthcare, activities, and — usually the largest single line — childcare. This layer varies enormously by country, because childcare subsidies, parental allowances and school costs are all national policy. There is no universal figure here, and any article that gives you one is guessing.
What you can do is estimate your own: find out what childcare costs where you live, add the recurring items you can name, and treat that total as a new fixed cost in the household budget.
Say your shared costs are €1,900 a month and the child adds €600. Shared costs become €2,500 — a 32 % increase in the household's fixed obligations, permanent for years.
Layer 3: the layer that actually dominates
Lost income. One parent reduces hours, takes leave, or steps back from a career track. This is almost always larger than layer 2, and it is the one couples under-plan, because the cost you can see is not the cost that hurts.
Consider incomes of €3,200 and €2,400, with €1,900 of shared costs. Split in proportion to income, each partner puts in about 34 % of what they earn — €1,086 and €814.
Add the child's €600 and the same proportional split becomes €1,429 and €1,071: both partners now spend 45 % of their income on the household. Uncomfortable, but survivable.
Now let the second partner take extended leave and drop to €600 of parental income. The household's combined income falls to €3,800 while shared costs stay at €2,500. The proportional split now consumes 66 % of each partner's income. Nothing about the child's own costs changed between these two scenarios — only the income did, and it moved the household twice as far.
What this means for planning
- Plan the income layer first. How long will either of you be out, and on what replacement income? That answer sets everything else.
- Rebuild the emergency fund target before the leave, not during it. A household that drops to one income needs a bigger buffer at exactly the moment it can no longer save. Six months of costs, not four.
- Re-agree the split. A proportional split recalculated on parental-leave income is not a favour; it is the same rule applied to new inputs.
- Compress layer 1, budget layer 2, insure layer 3. Second-hand equipment for setup, a fixed line in the budget for recurring costs, and savings plus whatever income protection you have for the third.
Model your own numbers
The couple budget planner has a field for extra shared pressure — put your estimated monthly child cost there and it shows what the household split becomes, and what each of you is left with. Run it twice: once on today's incomes, once on the leave scenario.
The buffer question first
Before any of this, the household buffer has to be sized for a single-income period — one emergency fund or two covers what changes. And if you have not had the wider conversation yet, the 12 questions for couples is where the inputs come from.