Guide
How to split family vacation expenses
A holiday shared between several households raises a question friends' trips never do: how do you count children, and do you settle per person or per family?
Weighting is a deliberate compromise
Counting a child as an adult penalises large families; not counting them at all penalises couples without children. The 0.5 coefficient isn't an accounting truth or an official standard — it's one example of a readable rule, which any group is free to adjust or replace, as long as it is agreed before leaving.
Formula
household share = amount × household shares ÷ total shares, with adult = 1 and child = 0.5
Worked example: three households, twelve shares
Three families rent a house and share the food shop, £2,340.00 in total. Family A has 2 adults and 4 children (4 shares), family B 4 adults and 2 children (5 shares), family C 2 adults and 2 children (3 shares). Total: 12 shares.
| Household | Composition | Shares | Amount owed |
|---|---|---|---|
| Family A | 2 adults, 4 children | 4 | £780.00 |
| Family B | 4 adults, 2 children | 5 | £975.00 |
| Family C | 2 adults, 2 children | 3 | £585.00 |
| Total | 8 adults, 8 children | 12 | £2,340.00 |
Check: 780.00 + 975.00 + 585.00 = £2,340.00. One share is worth £195.00 here. A flat per-head split (16 people) would give £146.25 each, i.e. £877.50 for family A — £97.50 more, purely because their children would count as adults.
Making the accounts acceptable
Agree the rule before booking. Weighting is very hard to discuss once the money has been spent.
One contact per household. Each family nominates someone who pays and receives: three counterparties beat sixteen.
Children's activities stay with their parents. A theme park or a kids' club doesn't concern households who sent nobody.
Frequently asked questions
Should a child count as a full adult?
That is for the group to decide before leaving. A 0.5 weighting per child for accommodation and food is one example of a simple, readable rule. For costs where age changes nothing, such as a hire car, count per household or per adult.
Per person or per household?
Weighted per person, but settled per household: one transfer per family instead of four. This keeps the settlement easier to read when several generations travel together.
What about grandparents who want to treat everyone?
Record the gift as an expense paid by them and split normally, then an equivalent repayment from them: the accounts stay exact and the gesture stays visible.
What if one family arrives later?
Split accommodation pro rata by each person's nights, keeping the child weighting. Everything else follows actual presence.
Editorial review — Written and reviewed by the Pivunio team. The methods described here are the ones the app itself uses, and they are covered by automated tests.