How to calculate a travel budget day by day

The usual way to calculate a travel budget per day is to look up what a day in that country costs on average, multiply it by the length of the trip and add the flights. It is a reasonable way to decide whether you can afford a destination at all. It is a poor way to know what this particular trip will cost, because none of your days will be average.

An average daily cost describes somebody else's trip. Your budget should describe yours, one day at a time.

Three layers, priced three ways

Most budgets go wrong because everything is poured into one pot. Before pricing anything, split the trip into three layers, because each one is estimated differently:

• Once per trip: getting there and back, travel insurance, checked luggage and any entry paperwork.
• Once per night: where you sleep, plus any tourist tax charged per person per night, which some places collect on arrival rather than in the booking price.
• Once per day: what you eat, what you visit, how you get around, and the small change in between.

The first two are mostly known before you leave: you can book them and write down the real figure. The third is where budgets fail, and it is exactly the part an average guesses.

Work out the travel budget per day from the plan

A day spent in two museums and a day spent at a market and in a park cost very different amounts, even in the same city. So instead of one number for every day, price each day from what is actually in it. For every day of the plan, write a line for each of these:

• Entry tickets and guided visits, at the price of the ticket you will really buy, not the cheapest one on the page.
• Each meal, priced as the kind of place you will actually eat in. A sit-down lunch and a sandwich on a bench are different lines.
• Local transport: count the rides the day needs first, and only then compare single tickets with a day pass.
• Anything sold in timed slots, and whether booking it online adds a fee.

Write each figure as a range: the cheaper version of that lunch and the one you will probably end up having. Add up the day and you get two numbers, a floor and a realistic ceiling. The budget for the trip is the list of those ranges, day by day, not their average.

The list also shows why a day is expensive. A heavy day is usually one or two paid sights plus a lot of rides, and planning the day by neighbourhood cuts the rides before you have given up anything you wanted to see.

Traveley builds its estimate the same way: the approximate cost per person it shows for a trip is added up from the prices of the stops on the plan, in the local currency, with a conversion to yours when it can make one. Where you sleep, how you get there and around, shopping and nights out are left out on purpose: those are costs you price better yourself.

Three days, three different budgets

Take a three-day city trip and look only at the daily layer:

• Day one, arrival: the transfer from the airport, a transport card, a coffee at the station and dinner near where you are staying. Hardly any sightseeing, yet the transfer alone can be the largest single item in the daily layer.
• Day two, museums: two entry tickets, a sit-down lunch between them and four rides across town. The most expensive day of the three, and most of it is tickets.
• Day three, a market and a park: free entry almost everywhere, lunch from the market stalls, everything on foot. A fraction of day two, with no sense of having missed anything.

An average would have been wrong on all three days. And if the total is too high, the list shows which ticket or which meal is pushing it up, so you can cut that instead of trimming a little from everything.

Arrival and departure days cost more than they look

First and last days are short on time, so it is tempting to budget them as half days. In money they are often full ones. Eating at an airport or a station costs more than eating in town, transfers get paid for in a hurry, and an evening flight can mean paying for left luggage so you can still use the last morning.

Plan them as light days for your legs, as the guide to how many things fit in one day recommends, but price them as full days for your wallet.

The small costs nobody writes down

None of these is large on its own; together they are why a careful budget is already over by day three. Give them a line in every day, or go through the list once before you leave:

• Rides you did not plan: the taxi when it rains, the bus back when your feet have had enough.
• Water, coffee and snacks between stops.
• Tips where they are expected, and service charges already added to the bill.
• Public toilets, cloakrooms and lockers that charge.
• Your bank's fees for paying by card or taking out cash abroad, plus whatever the cash machine charges on top.
• Mobile data, if your plan does not cover the country.
• Small entrance fees at churches, gardens and viewpoints you only decided to go into once you were outside.

Budget in the local currency, convert once

Price the days in the currency you will actually pay in. It is the number on menus and ticket windows, so it is the one you can check on the spot. Then convert the total into your own currency once, write down the rate and the date you used, and round against yourself rather than in your favour.

Two habits protect that conversion once you are there. When a card terminal or a cash machine offers to charge you in your home currency, say no and pay in the local one: the rate on that screen is set by whoever runs the machine, not by your bank, and it is rarely the better deal. And if the currency moves a lot, check the rate again the week you leave rather than trusting the one from the day you booked.

A buffer sized to what you do not know

The common advice is to add a flat ten or fifteen per cent. It is better than nothing, but it treats every line the same. A ticket you have already bought needs no margin at all; a dinner you guessed at needs a wide one. Your ranges already carry most of that uncertainty, so the buffer only has to cover what no range can: a missed connection, a pharmacy, a night somewhere you did not plan to sleep.

Keep it apart from the daily budget, and do not spend it on day two because a restaurant looked good: it is not extra spending money, it is what stops one bad day from spoiling the rest.

Check it every evening, not at the end

A budget worked out per day has one more advantage: you can hold it up against reality while there is still time to react. Each evening, put what the day really cost next to what you planned. If day two ran over, you know on day two, and the lighter day three can absorb it. Find out on the last night and there is nothing left to adjust.

That is the whole method: three layers, each day priced as a range from its own plan, the small costs written in, the local currency first, a buffer kept apart, and a check every evening. An hour before you leave buys you a total you can rely on rather than one you hope for.