Trip expense calculator

One booking, one price, and people who came and went on different days — this is the calculation that starts most arguments. Put in the total, the number of nights and who was there for which of them, and the split appears as you click.

Accommodation is one line. The rest of a trip is flights, transfers, car hire, fuel, dinners, tickets and the boat trip half the group skipped — paid by different people, shared by different people. Put them in and the calculator works out where everyone stands.

Note the day trip in the example: Sef paid $90 and only Sef and Ada went, so it never touches Mia or Leo. A calculator that divided every expense by four would have charged them $22.50 each for a boat they were not on — the single most common way a group split goes wrong.

More than one plan can be correct

When the calculator says three payments will clear a group, that is one valid set of three, not the only one. Any plan that leaves everyone at zero is equally correct, and there are usually several. If you have seen a different three-payment answer for the same numbers — including in the same trip worked through in pounds on the trip expenses page — both are right.

The same calculator covers most of the ways a group ends up owing each other money on a trip. What changes is which method you pick and who you tick.

Splitting an Airbnb or holiday rental

Enter the total the host actually charged — including the cleaning and service fees, not the nightly rate the listing advertised — then tick the nights each person stayed. For a place booked as one lump for the whole period, the equal nightly rate is usually the least contentious answer.

Splitting a hotel room by night

A room genuinely billed per night is the case “split each night separately” was built for: each night is divided between the people in the room that night, so two people who stayed on after the others pay the full cost of the nights they had to themselves.

Rooms that are not equal

A villa where one couple has the suite and someone else has the box room is the hardest case, because nights are not the difference — the rooms are. Two approaches work here. Either agree a figure per room and enter each room as one “person” in the calculator above, then halve the couple's share between them. Or set aside a portion of the total for the shared space, split that equally, and divide the rest by room. Whichever you choose, agree it before anyone sees the booking.

Road trip costs: fuel, tolls and the hire car

Fuel, tolls and parking have nothing to do with nights, so they belong in the second calculator rather than the first — enter each one with whoever paid it. A hire car charged by the day is the exception: put it in the first calculator and split each night between whoever had the car.

Meals and activities only some people joined

The boat trip four of six went on, the dinner two people skipped, the taxi one person took alone. Add each as its own expense in the second calculator and untick everyone who was not part of it. This is where an even split gets a group's numbers wrong, and it is the whole reason per-expense participants exist.

Someone paid before the trip

The deposit paid in March, the flights one person booked for four, the tickets bought months ahead. These are shared expenses with a single payer, and they are the figures groups most often forget — see the list further down.

None of the three is objectively right — they encode different ideas about what the money bought. Pick the one whose assumption your group actually agrees with, and pick it before anyone sees what they would personally pay under each.

The practical advice: for a house or villa booked as one lump, the equal nightly rate is the least contentious. For a hotel room genuinely billed per night, splitting each night matches what was actually charged. For a weekend everyone signed up to, an equal split saves a conversation nobody needs to have.

Same trip, same $640, three methods, three different answers. Four people take an apartment in Lisbon for four nights; Sef arrives a day late and stays three.

Why the last cent does not always match

640 does not divide by 15, and 160 does not divide by three. Rather than round each share and quietly lose or invent a cent, the calculator divides in whole cents and hands the remainder to whoever was rounded down hardest — which is why one person pays a cent more and the column still totals exactly $640.00. An expense calculator whose column does not add up to the bill is worse than no calculator.

1. 1

   Enter the total and the nights

   Put in what the booking cost in full, how many nights it covered, and how many people are sharing it. Rename each person so the result is readable when you paste it into the group chat.

2. 2

   Tick the nights each person stayed

   Fill in the attendance grid. Click a name to select someone's whole stay, click a night number to select everyone for that night, or click and drag across the grid. Leave a cell empty for a night someone was not there.

3. 3

   Choose how to divide it

   Pick one of the three methods: everyone pays the same, everyone pays the same nightly rate, or each night is divided between the people there that night. The result updates as you switch, so you can compare before agreeing on one.

4. 4

   Add the rest of the trip

   Use the second calculator for everything else — flights, car hire, dinners, the day trip only half the group went on. Record who paid each one and untick anyone who did not share it.

5. 5

   Settle up

   Read off who owes whom. Choose between paying back whoever paid, which traces every payment to a real expense, or the fewest payments, which clears the balances in as few transfers as possible.

The figures a group misses are almost never the dinners. They are the things paid weeks earlier by one person, when nobody was thinking about splitting anything yet.

• The deposit. Usually paid months ahead by whoever booked, often on a different card, and routinely left out of the total at the end.
• Flights and trains booked separately. If one person booked for several people, that is a shared expense with one payer, not four private purchases.
• The cleaning or service fee. Part of what the booking cost. Enter the total actually charged, not the nightly rate the listing advertised.
• Fuel, tolls and parking. Small, frequent, paid in cash, and forgotten by the person who paid them.
• The supermarket run. One trolley, one card, everybody eating from it for three days.
• Anything paid for someone who is not on the trip. A friend who dropped out but still owes for a non-refundable ticket belongs in the calculation.

Said plainly, because a tool that hides its limits wastes your time later.

• It does not convert currencies. One calculation, one currency, chosen from USD, GBP, EUR, INR, CAD, AUD, AED, PKR. Converting means picking a rate and a date, and any choice silently changes what someone owes. If a trip spanned two currencies, run it twice and settle each, or agree a rate between yourselves first. Expenddy applies no exchange rate anywhere, in the calculator or in the app.
• It does not save anything. Everything is held in this browser tab and gone when you close it. That is why it needs no account — but it also means a trip you are still adding to over several days does not belong here.
• It is not shared. The others cannot see what you typed or add their own receipts. You can copy the result as text and paste it to them, and that is the whole of the sharing.
• It does not move money. It tells you who should pay whom. Expenddy is a record-keeping app, not a bank or a payment service, and never holds or transfers money.

For a trip that is still happening — where expenses arrive daily, several people are adding them, and everyone wants to see the same running balance — that is what the Expenddy app is for. It keeps the ledger, updates the balances as expenses come in, records settlements when people actually pay, and exports the lot to CSV. Same arithmetic, kept for you and shared with the group.