How does the Who Owes Who calculator work?
- Add everyone involved — just first names are enough.
- Add each shared expense, like a hotel, dinner or groceries.
- Record who paid for it and who took part.
- The calculator works out everyone's fair share of each expense.
- It calculates each person's balance: what they paid minus what they should pay.
- It simplifies the balances into a small number of payments.
How is who owes whom calculated?
For every person: balance = amount paid − fair share of the expenses they took part in.
A positive balance means the person should receive money. A negative balance means they owe money. All balances always add up to zero.
The calculator then matches people who owe money with people who are owed money to simplify the settlement — for example, people whose balances cancel out exactly are settled with each other first.
Worked example
| Person | Paid | Balance |
|---|---|---|
| Sarah | €240 | +€130 |
| Mike | €120 | +€10 |
| Anna | €80 | −€30 |
| John | €0 | −€110 |
Total €440, so each person's fair share is €110.
John pays Sarah €110 · Anna pays Sarah €20 · Anna pays Mike €10.
Why simplify the payments?
If everyone paid everyone back expense by expense, a group of six could need up to 15 separate transfers.
Because only the final balance matters, the calculator combines everything into at most one payment fewer than the number of people — usually far fewer.
Frequently asked questions
Is Who Owes Who free?
Yes. The calculator is completely free to use and is supported by ads.
Do I need an account or an app?
No. It works in your browser on any phone or computer, with no signup and nothing to install.
Where is my group stored?
Your group is saved only in your own browser. It isn't uploaded to our server. If you share a link, the group's names and amounts are packed into the link itself, so anyone with the link can see them.
What if someone didn't take part in an expense?
When adding an expense, untick the people who weren't involved. They won't be charged a share of it.
Can I split unequally?
Yes. Each expense can be split equally, by custom amounts, or by percentages.
How many payments will it suggest?
A small number. It looks for people whose balances cancel out and settles them together, and never needs more payments than one fewer than the number of people. Very large groups use a fast method that needs at most one payment fewer than the number of people.
Which currencies are supported?
Every active ISO 4217 currency. Pick one next to the group name; amounts are calculated to two decimals and shown in that currency's usual format.