Sharing a vacation rental with two or three families

When three families rent a house together, splitting per person charges a toddler as much as an adult, and splitting per family charges a single parent as much as a household of four. Neither method is wrong. The group just needs to pick, for each kind of expense, the unit that matches what people actually use: the household, the bedroom or the person.

Lodging: per household or per bedroom

A house costs the same whether two or five children sleep in it. Dividing the rent per person therefore makes larger families pay more for a roof everyone shares. Two simple rules usually work better.

• Per household: each family pays the same share. This is easy to read when families use comparable space.
• Per bedroom: divide the price by the number of bedrooms, and each family pays for the rooms it uses. This is fairer when one family takes two rooms and another takes one.

If families arrive or leave on different days, nights matter as well as rooms. That case is covered in our guide to splitting a rental by nights.

Groceries: agree on a child share

For food, counting people makes more sense, but a four-year-old does not eat like an adult. Many families agree on a reduced share for children, such as half a share. There is no official rule for this kind of split; it is an agreement between you, best settled before the first grocery run.

For a sense of scale, France’s statistics institute, INSEE, compares living standards across households of different sizes with an equivalence scale: 1 unit for the first adult, 0.5 for other people aged 14 or over, 0.3 for children under 14. The scale reflects economies of scale within a household. It is built for income statistics, not for splitting vacation groceries, but it shows that a child share below an adult share is a common convention.

A week with three families, in numbers

This example is fictional. Three households share a house for a week. The Millers are two adults and two children under 14. The Okafors are two adults and one child. Nadia comes alone with her 15-year-old son. The group agrees to split lodging per household and groceries with a half share for each child under 14, counting the teenager as an adult.

• Lodging: $1,800, paid by the Millers. Per household, $600 each.
• Groceries: $630, paid by the Okafors. The Millers count 3 shares (2 adults, 2 half shares), the Okafors 2.5, Nadia and her son 2. That is 7.5 shares of $84: $252 for the Millers, $210 for the Okafors, $168 for Nadia.
• A boat trip at $30 per person, booked by the Okafors for the two families going: $120 for the four Millers, $90 for the three Okafors, $210 in total. Nadia and her son skip it.

Each household’s share: Millers, 600 + 252 + 120 = $972. Okafors, 600 + 210 + 90 = $900. Nadia, 600 + 168 = $768. The total is $2,640, exactly what was spent (1,800 + 630 + 210).

The Millers paid $1,800 toward a $972 share, so they are owed $828. The Okafors paid $840 toward a $900 share, so they owe $60. Nadia paid nothing and owes $768. Two repayments settle the week: Nadia sends the Millers $768, and the Okafors send them $60.

For comparison, splitting the house per person (9 people, $200 each) would charge the Millers $800 and Nadia $400. Splitting per household favors large families; splitting per person favors small households. Splitting per bedroom often lands in between. Choose the rule together and apply it to the whole week.

What each family pays on its own

Not everything needs to go through shared accounts. Water park tickets paid at the counter by each family, ice cream, a souvenir: if each household pays directly for what it uses, there is nothing to split. Only record what one household paid for another.

Families often have different means. Deciding ahead of time what is shared and what stays optional keeps any family from being pulled into spending it did not plan for. The method is covered in planning a trip with different budgets.

One account per household, not per person

To track these costs, it is often simpler to treat each family as a single participant: one parent per household records expenses and receives the balance. Children do not need to appear; their share is reflected in the household’s.

Spliz lets a group add each expense, split the shares and see everyone’s balance, for free. Other participants install the app to join the group as guests, without creating an account. Repayments happen outside the app, by bank transfer, in cash or with another app, and can then be recorded in the group. Recording a repayment does not transfer money.

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Sources

• INSEE, consumption unit, the equivalence scale known as the OECD scale (1; 0.5; 0.3), updated December 16, 2022.
• Spliz, available features, what the app does today.