Split Expenses and Settle Up
Enter who paid for what, get the shortest list of payments that settles everyone up.
In short
To settle shared expenses, total what each person paid, divide the overall total by the number of people to get each fair share, then compare. Anyone who paid more than their share is owed the difference. Matching the largest debtor to the largest creditor repeatedly gives the fewest transfers.
Last reviewed
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The arithmetic
Three steps, and the first two are the ones people do in their heads badly.
- Total everything paid. Not per person, the whole trip.
- Divide by the number of people to get each fair share. Where an expense only covers some of the group, that expense is divided among those people rather than everyone.
- Compare. Paid more than your share and you are owed the difference. Paid less and you owe it.
The balances always sum to zero. If they do not, an expense has been entered twice or missed.
Why the settlement has fewer payments than you expect
With five people you might expect a tangle of ten small transfers. Usually four will do, because debts net out.
If Ana owes Ben £20 and Ben owes Cai £20, there is no need for two payments. Ana pays Cai £20 and Ben is finished without moving any money at all.
Repeatedly matching the largest debtor against the largest creditor produces a settlement with at most one fewer transfer than there are people. It is not always the theoretical minimum, which is a genuinely hard problem to solve exactly, but it is close and it is instant.
The mistake that causes arguments
Splitting everything equally when not everyone was there.
Two people skipped the expensive dinner. One does not drink. Someone arrived a day late. Divide the total by five and those people quietly subsidise everyone else, which is the thing that sours a trip afterwards.
Ticking only the relevant people per expense takes seconds and removes the entire problem. It is also much easier to do as you go than to reconstruct at the end.
Practical advice for group trips
- Record it the same day. Nobody remembers the taxi on Tuesday by Friday.
- Take photos of receipts rather than trying to remember amounts.
- One person pays for each category where possible. Fewer, larger expenses are far easier to settle than dozens of small ones.
- Agree the rules first. Are drinks shared or individual? Is the driver reimbursed for fuel? Five minutes at the start beats an argument at the end.
- Settle promptly. The longer it sits, the more awkward asking becomes.
- Round in the other person's favour on small amounts. Chasing 40p costs more goodwill than it recovers.
Shared houses
The same arithmetic works for rent, bills and shared shopping, with one addition: costs that are not split evenly. A larger room paying more rent, or one person on a different contract, is handled by entering their share as a separate expense rather than trying to weight the split.
For anything recurring, settle monthly on a fixed date. Balances that accumulate for half a year become large enough to be a real problem for whoever is behind.
Nothing is stored
Calculated entirely in your browser. Nothing is transmitted, which also means nothing persists when you close the tab, so copy the settlement before you leave.
Frequently asked questions
How do I work out who owes what after a trip?
Total everything paid, divide by the number of people to get each fair share, then compare each person's spending against that share. Anyone above it is owed money, anyone below owes it. The tool then works out the smallest set of transfers that settles everyone.
Why does it suggest fewer payments than people?
Because debts can be netted. If Ana owes Ben and Ben owes Cai the same amount, Ana can pay Cai directly and Ben drops out entirely. Repeatedly matching the largest debtor to the largest creditor produces a settlement with at most one fewer transfer than there are people.
Can some people be excluded from an expense?
Yes. Tick only the people an expense should be split between. A meal three of five people attended is divided three ways, and the other two are unaffected. This is the usual reason a simple total-and-divide gives the wrong answer.
Are the amounts saved anywhere?
No. Everything is calculated in your browser and nothing is transmitted or stored. Closing the tab clears it, so copy the settlement before you leave if you need it.
What about rounding?
Shares are calculated to the penny and transfers rounded to two decimal places, so a settlement can be off by a penny or two across a large group. The tool flags it when the rounded transfers do not exactly balance.