What a trip really costs — and why it always comes out higher

A holiday gets planned as one number and paid in a dozen, spread over half a year. How to work it out in advance, and how to find out afterwards what it actually was.

Almost every trip costs more than planned. Not because people are bad at arithmetic, but because they count one thing and pay a dozen, spread across months.

The hotel deposit goes out in March. You buy flights in May because they were cheaper then. Insurance a week before. On the ground you spend every day. Airport parking gets paid after you are back. Each of those lands in a different monthly budget, and none of them looks like "the holiday" — each looks like an ordinary expense in March, May and July.

What usually goes missing

When someone says "the trip cost us two thousand", they usually mean flights and accommodation. That can be half the real number.

Getting to the airport and back. A week of parking, a train, or a taxi for four. It can cost more than one of the tickets.

Food above what you would have eaten anyway. The number that matters is not the total spent on meals but the difference — you would have eaten at home too. Over two weeks that difference is usually substantial.

Local transport. Car hire, fuel, tickets, the ride from the airport.

Entry fees and attractions. The easiest thing to leave out when planning and the hardest to refuse once you are there.

Things bought for the trip. A suitcase, shoes, a swimsuit, an adapter. Those are trip costs even if they went out two months earlier under "clothes".

Insurance, visas, baggage fees. Small individually, several hundred together.

A rule that beats a careful calculation

Add up what can be added up — flights, accommodation, transport — and add thirty percent. Not because that is a nice round figure, but because that is roughly what comes out of the things nobody plans.

That margin shrinks over time, but only if you record things. After your second or third trip you will know what it actually is for you — maybe fifteen percent, maybe fifty because you always hire a car.

Recording spending that is scattered across months

This is the real problem. A budget category has a monthly limit, so a trip spread over six months does not fit in any of them. March's deposit disappears into March's "food and fun", and when you get back there is no way to add the whole thing up.

That is what projects are for. A project gathers spending around an occasion rather than around a month or a type. Dinner at a taverna is both "Food", because that is the kind of spending, and "Greece", because that was the occasion — and both facts survive.

In practice: you create a project called "Greece 2026", enter a planned amount, and from then on every trip-related expense gets assigned to it as you add it to your budget. The deposit in March, flights in May, everything on the ground in July. When you get back you have one number and a breakdown by category.

Money coming back counts too

Something usually comes back from a trip: a refund for a cancelled hotel, a share paid by whoever travelled with you, a tax refund on tickets. A project takes income as well and subtracts it from the spending, because only the difference answers what the trip cost you.

Why bother knowing

Not to be put off. To put aside the right amount next time.

A trip you know costs three thousand gets planned differently from one you think costs two — and which then lands on a credit card in September. That difference, not the number itself, decides whether the holiday ends when you get home or three months later.

If you are saving towards a specific trip, the required monthly amount falls straight out of the goals module — and it is that figure, not the target, that tells you whether the date is realistic.