Units, and why each category has its own
Airfare, activities and insurance are per person. Lodging is per room per night, which is not the same as per person, and treating it as per person is the single most common way a group trip budget comes out wrong. Food is per person per day. Local transport and shopping are entered as a whole-trip total, because neither scales cleanly with either people or days.
Keeping the units separate means the trip can be resized without redoing anything. Change the party from two to four and the airfare, food and activity lines all follow, while lodging follows only if you also change the room count, which is exactly the behaviour you want, since four people might take one larger unit or two rooms and the arithmetic differs.
Nights are entered separately from days because they are rarely days minus one. A red-eye out and a late return can make a seven day trip five nights of paid lodging, and a trip that starts with an overnight flight loses a night at each end.
Enter the price you will actually be charged
Two categories are routinely entered too low. Lodging quoted per night is a headline rate; the figure to use is the final total at checkout divided by the nights, after occupancy tax, resort fees, cleaning fees and parking. On a booking site this is visible only on the last screen, and it is frequently twenty to thirty percent above the rate on the search results.
Airfare has the same problem in a smaller form. A fare that excludes a checked bag, seat selection and a carry-on on a basic economy ticket is not the price of the flight. Add what you will actually pay, in both directions, per person.
The contingency is not padding
Travel spending overruns in small increments rather than large ones: a taxi because the last train had gone, a paid locker, an entry fee that was cash only at a higher rate, a pharmacy, a meal at the airport because the connection was long. None of these is a planning failure and none of them is individually worth budgeting for.
Setting a contingency changes what happens when they arrive. Without one, the third unplanned expense feels like the budget is broken and produces either a bad mood or a decision to stop tracking. With one, the same expenses are simply the contingency doing its job, and if the line is not used it comes home as money. Twelve percent is the default here as a working figure; it is not derived from any study, and the right size depends on how much of the trip is prepaid and how unfamiliar the destination is.
Foreign currency and card charges
The exchange rate field takes foreign units per dollar, so 0.92 for euros or 148 for yen, and converts the total for comparison against local prices. It is a display conversion at one rate on one day and nothing more.
What it does not include is the cost of moving money. A card with a foreign transaction fee typically adds around three percent to every purchase abroad, an ATM abroad adds a withdrawal fee at both ends, and dynamic currency conversion — the machine offering to charge you in dollars — is close to always the worse rate. If you are paying with a card that charges the fee, adding two to three percent to the on-the-ground portion is closer to the truth than the raw conversion shown here.
After the trip, not before
This page plans a trip. Dividing what was actually spent afterwards is a different problem, because by then the question is who paid for what rather than what things cost. The travel expense split takes a list of expenses with who paid and who each one covered, and the group trip settlement handles the case where people were present for different numbers of nights and the shared costs should divide accordingly.
Questions people ask
How do I budget for children who eat less and sometimes travel free?
The party size drives food, activities and airfare together, so the cleanest approach is to keep the head count at the true number of people and lower the per person per day food figure to the group average. For a child on a lap fare, the airfare field will be too high, so enter the average airfare across everyone rather than the adult fare. Both adjustments keep the totals right even though no individual line matches one traveller.
Should a rental car go in local transport?
Yes, with everything that comes with it: the daily rate for the whole rental, fuel, tolls, parking at the lodging, and any young driver or additional driver charge. It is entered as a whole-trip total rather than a daily rate because the charges attach at different points and a per-day figure hides the ones that do not.
What is a reasonable food figure per person per day?
There is no useful general answer, because it varies by destination by a factor of five and by traveller by a factor of three at the same destination. The way to get a real number is to look up two or three actual places you would eat at the destination, price a day of meals as you would actually eat them including coffee and drinks, and use that. A figure taken from a travel article is a figure from someone else’s trip.