One late arrival changes the whole calculation
Four friends share a trip, but Dev joins only the last night. They agree to split the rental by nights stayed and other expenses only among the people involved. These are negotiated choices, not universal rules for bookings.
| Expense | Paid by | Who shares it? | Total |
|---|---|---|---|
| Rental | Ana | Ana, Ben, Cara: 3 nights each; Dev: 1 | $900 |
| Boat trip | Ben | Ana and Ben | $120 |
| Groceries | Cara | All four equally | $80 |
The rental has 10 person-nights, so each night costs $90. Ana, Ben and Cara owe $270 each; Dev owes $90. The boat adds $60 each to Ana and Ben. Groceries add $20 each to everyone.
Final expense shares are Ana $350, Ben $350, Cara $290 and Dev $110. Ana paid $900, Ben $120, Cara $80 and Dev $0. Before any repayments, Ana is owed $550.
Ben has already sent Ana $100. That leaves Ben paying Ana $130, Cara paying Ana $210, and Dev paying Ana $110. The remaining transfers total $450. Do not add Ben’s $100 repayment as a new expense: that would incorrectly increase the trip’s $1,100 cost.
Record the cost and the agreement separately
For every expense, keep a description, total, payer, and who it covers. Use the checkboxes for equal participation. Under “Unequal shares or nights,” a 3, 3, 3, 1 split represents the rental above. A zero excludes someone; it does not erase an amount they already paid.
If two people paid one expense, enter two rows for their respective payments using the same allocation weights. For example, a $100 dinner paid $60 by Ana and $40 by Ben becomes two rows totaling $100. For a refund, reduce the original expense to its net cost only if the original payer received the refund; otherwise record and reconcile who received it before settling.
Agree on cancellations before booking
Person-nights work when the group has agreed to them. They can shift a non-refundable booking onto the remaining travelers if somebody cancels. Decide whether everyone retains their booked share, whether a replacement takes over, or whether the group redistributes the cost. The calculator applies your agreement; it cannot decide which agreement is appropriate.
Why you might pay someone who did not buy your ticket
The calculator combines each person’s balance across all expenses. You may repay someone who covered lodging even if another friend bought your tour ticket. The purpose is to settle the group’s overall balances. If the group needs each expense reimbursed directly to its payer, settle those expenses separately instead.
A positive balance means the person should receive money; a negative balance means they still owe. After the proposed transfers, every balance is zero. The plan is deterministic, but it is not guaranteed to use the mathematically smallest number of transfers.
Mixing currencies without mixing estimates
This calculator uses one currency for the whole trip. Convert each expense using an agreed basis before entering it. For actual reimbursement, use the payer’s posted cost and separately identify any fee. Keep the original receipt and conversion beside your ledger so someone can trace the number. The posted-charge calculator helps allocate a converted bill.
Close the trip with a checkable record
Copy the summary into your group chat, check that each expense is included exactly once, and confirm earlier repayments before anyone sends money. A suggested repayment is not a payment confirmation. If a transfer happened after you copied the summary, enter it and generate an updated plan.