--- title: "Split Expenses Calculator: Who Owes Who | Friend Fête" description: "Free trip cost splitter for groups: add who paid what, split equally, by shares or exact amounts, and see who owes who in the fewest transfers." url: https://friendfete.me/ --- Trip cost splitter · who owes who # Split expenses with friends and see who owes who Add everyone in the group, then each expense and who paid it. The calculator works out **each person’s balance** and the **shortest list of payments that settles everyone**, to the cent. It is free, needs no sign-up, and your figures stay in your browser. ## How to split trip costs between friends Splitting a trip fairly comes down to one sum per person: **what they paid, minus their share of everything**. If the answer is positive, the group owes them; if it is negative, they owe the group. The calculator keeps that sum for everyone as you add expenses. 1. **Add the people.** Everyone who shares any cost, including whoever is typing. 2. **Add each expense once**, with the person who actually paid. If two people paid for the same thing, add two expenses. 3. **Choose how it is shared.** Equally between everyone, equally between some people only, by shares, or by exact amounts. 4. **Read the result.** The plate shows everyone’s balance and the transfers that settle the group, with the full ledger underneath. ### A worked example: a weekend for four The example already on the page is a weekend at a lake cabin. Alex booked the cabin for €480.00, Bea bought €93.17 of groceries, Chen paid €61.40 for fuel and €45.00 for wine, and Dee paid €154.00 for dinner at the pub. Alex’s share of everything comes to €203.77: a quarter of the cabin (€120.00), of the groceries (€23.30) and of the fuel (€20.47), his own €32.50 dinner, and one of six wine shares (€7.50). He paid €480.00, so the group owes him €480.00 − €203.77 = **€276.23**. The other three owe €126.59 (Bea), €103.35 (Chen) and €46.29 (Dee), which adds up to exactly the €276.23 Alex is owed. Three transfers, all to Alex, settle the weekend. Balances always add up to zero: what the debtors owe is exactly what the creditors are owed. ## Equally, by shares, exact amounts or some people only - **Equally** suits shared things everyone used: the accommodation, the communal shop, a taxi you all took. - **Some people only**: untick anyone who wasn’t in on it. Dee came by train, so the fuel is split between the other three. - **By shares** handles “twice as much” without arithmetic. Bea and Dee drank most of the wine, so they have 2 shares each and Alex and Chen 1: six shares of €7.50. - **Exact amounts** is for itemised bills such as a restaurant where everyone ordered differently. The amounts must add up to the total; the form tells you how much is still unassigned. ## Where the odd cent goes €93.17 does not divide by four: each quarter is €23.2925. Every share is rounded down to the cent (€23.29), which leaves one cent over. Leftover cents go one each to the people whose shares lost most in the rounding, and when those are equal, to whoever is higher in the people list. So Alex pays €23.30 and everyone else €23.29. Nobody ever pays more than one extra cent on an expense, and the shares always add up to the exact total. The plate lists every expense that needed rounding and who covered the cent. ## How the fewest transfers are found Once the balances are known, the money still has to move. Paying each other back expense by expense can take dozens of transfers; settling the balances takes far fewer. The calculator first pairs off anyone who owes exactly what someone else is owed. Then, again and again, the person who owes the most pays the person owed the most, as much as clears one of them. Each step settles at least one person, so a group of *n* people never needs more than *n* − 1 transfers. That is the fewest possible in most groups, but not in every case. Finding the true minimum means finding the most separate subgroups whose balances cancel out, and Tom Verhoeff showed that this version of the problem is NP-hard: no known method solves every large case quickly. A small example where the shortcut misses: Amy is owed €60 and Ben €40, while Cara and Dan owe €30 each and Eve and Finn €20 each. Cara and Dan could pay Amy, and Eve and Finn pay Ben: four transfers. The largest-to-largest rule finds five. For a group of friends the difference is rarely more than one transfer. ## Sharing the tally with friends The **share link** holds the whole tally after the # in the address, compressed. Browsers keep that part of a link to themselves: it is not sent to the web server when the page loads, so your expenses never reach us. Anyone who opens the link sees the same figures and can add to them; send the new link back to share their changes. Long tallies make long links. Web standards ask software to cope with addresses of at least 8,000 characters, but chat and email apps vary, so above 2,000 characters (our own cautious limit) the page suggests sending the **CSV file** instead. The CSV opens in any spreadsheet: one row per expense with Description, Amount, Paid by and Split, then one column per person holding a 1 for an equal split, a number of shares, or an exact amount. Import it here to carry on. Your tally is also **saved in this browser**, so it is still there when you come back. Start a new tally to clear it. ## Common mistakes - **Leaving the payer out of the split.** If Alex pays for four people’s dinner, Alex is one of the four. Untick the payer only if the expense really was a gift or wasn’t theirs. - **Adding a refund as a new expense.** If part of a booking came back, edit the original amount instead. - **Mixing currencies.** The calculator does not convert. Turn everything into one currency first, at the rate you actually paid. - **Settling expense by expense.** Five people paying each other back for twenty receipts can take forty transfers. Settle the balances once, at the end. Renting a cottage for several nights where people come and go? The [holiday house cost split](https://friendfete.me/holiday-house-cost-split/) shares a booking by nights and room size and sends the result back here. ## More tools for trips and parties Plan it, play it, pay for it. - [Holiday house cost split](https://friendfete.me/holiday-house-cost-split/): Share a rental by nights stayed, with room weights for the en-suite, couples and shared extras. - [Left-right gift game](https://friendfete.me/left-right-gift-game/): Seven original stories to read aloud, a large-print mode, and a checker for writing your own. - [Christmas dice gift game](https://friendfete.me/christmas-dice-gift-game/): Printable rule cards, a big on-screen dice roller and a round timer. - [Find a date that works](https://friendfete.me/find-a-date/): Send a link, collect short answer codes, and see the best dates ranked. No accounts. - [Friendsgiving planner](https://friendfete.me/friendsgiving-planner/): Check the menu for gaps, dietary coverage and oven clashes before the day. ## Recommended Two free services for the online side of planning a trip or a party. Temporary email · no sign-up ### CleanTempMail Party-game printables, playlist sites and booking newsletters often ask for an email address first. CleanTempMail gives you a free temporary inbox at once, with no sign-up: pick a random or custom address on hundreds of domains, and messages are deleted automatically after 3 days. Keep your real address for bookings and tickets you need to keep. [Get a temporary inbox](https://cleantempmail.com/) Disposable cloud browser · domain lookups ### WebTraceCheck Found a holiday cottage or festival tickets on a site you have never heard of? WebTraceCheck’s free DNS and domain lookup shows how long a website’s domain has existed, and its disposable cloud browser opens unfamiliar links on an isolated desktop that is deleted after each session. Nothing to install, with free time every day. [Try WebTraceCheck](https://webtracecheck.com/) ## Questions **How do I work out who owes who after a trip?** For each person, add up what they paid and what their share of every expense comes to. Paid minus share is their balance: positive means they are owed money, negative means they owe it. Then the people who owe pay the people who are owed until every balance is zero. The calculator does both steps for you. **How do I split a cost between only some of the group?** Choose Equally and untick the people who were not part of that expense. The cost is shared evenly between the people left ticked, and the others are not charged for it. **Is this the minimum number of payments?** Usually, and never more than one fewer than the number of people. Exact matches are paired first, then the biggest debt is paid to the biggest credit. In rare cases a cleverer grouping saves one transfer; finding the true minimum for any group is a known hard problem. **Can my friends see and edit the same tally?** Yes: copy the share link and send it. The tally is inside the link itself, so whoever opens it sees the same expenses and can add more. Changes are not synced automatically; send the new link back afterwards. There are no accounts and no server copy. **Can I use it for a holiday house where people stay different nights?** Use the holiday house cost split for the booking: it shares the rent by nights stayed and room size, then opens the result here as expenses split to the cent, ready for the rest of the trip. **Does it convert currencies?** No. Pick one currency symbol for the whole tally and enter every amount in that currency, converted at the rate you actually paid. The symbol is only a label; the maths is the same for any currency. ## Sources - Settling debts in the fewest transfers is NP-hard: [Verhoeff T. Settling Multiple Debts Efficiently: An Invitation to Computing Science. Informatics in Education 3(1), 105–126 (2004)](https://doi.org/10.15388/infedu.2004.08). - The part of a link after # is separated before the page is requested: [RFC 3986, Uniform Resource Identifier: Generic Syntax, section 3.5](https://www.rfc-editor.org/rfc/rfc3986#section-3.5). - Software should support addresses of at least 8,000 octets: [RFC 9110, HTTP Semantics, section 4.1](https://www.rfc-editor.org/rfc/rfc9110#section-4.1). - CSV quoting: [RFC 4180, Common Format and MIME Type for Comma-Separated Values](https://www.rfc-editor.org/rfc/rfc4180). Link encoding: [RFC 4648, section 5 (base64url)](https://www.rfc-editor.org/rfc/rfc4648#section-5).