Split expenses calculator

Who owes who, without a spreadsheet

This expense splitter keeps a group's accounts over days or weeks: a road trip, a shared apartment, a ski weekend, a group gift, a bachelor party or a night out. People take turns paying; at the end, the tool shows each person's balance and a short list of repayments that settles everything.

You can keep several groups on your device, say the summer vacation and your roommates. For a single restaurant check, the tip calculator is quicker.

How to use it

1. Type a "Group name" and pick the "Group currency". "New group" starts another one.
2. Add 2 to 30 people with "Participant name" and "Add".
3. For each expense, fill in "Description", "Amount", "Date" and "Paid by", then tick the people involved under "Split between".
4. Read the "Balances" table ("Paid", "Share", "Balance") and the "Simplified repayments" list. Once a transfer is done, click "Mark as paid": it moves to "Repayments made" and the balances update.

How balances and transfers are worked out

A person's balance is what they paid minus their share of what was bought. Positive, the group owes them; negative, they owe. Balances always add up to zero.

Take three friends, A, B and C. A pays $90 of groceries for everyone, so $30 each. B pays a $30 cab ride for A and B, so $15 each.

The tool has the person who owes the most pay the person who is owed the most, as much as possible, then repeats. Here C sends $30.00 to A, then B sends $15.00 to A. Two transfers and everyone is square. Each transfer brings at least one person to zero, so a group of n people never needs more than n − 1 transfers. Finding the absolute minimum in every case is a much harder problem; this greedy method gives a simple answer that is always correct and often the shortest.

Uneven splits

The "Split" menu has four modes. "equally" divides the amount among the people ticked. "by shares" gives each person a weight: for a $500 cabin rental shared by a couple and three single friends, give the couple 2 and the others 1. That makes 5 shares of $100: $200 for the couple and $100 for each of the three. "by exact amounts" is for when you know each share; if they do not add up to the total, the tool shows the difference and refuses the expense. "by percentages" must total 100%.

Amounts are rounded to the cent. $100 split three ways gives 33.34 + 33.33 + 33.33 = $100.00: each person first gets their share rounded down, then the leftover cents go one at a time to the shares that were closest to the next cent, in list order when they tie. The shares always add up to the amount.

Foreign currency

Pick another "Currency" for the expense and type the "Exchange rate", meaning the value of one unit of that currency in the group currency. A €50 dinner at a rate of 1.08 counts as $54.00. The tool does not look up rates online: use the one on your card statement.

Privacy

Everything is calculated in your browser and the groups stay saved on this device. "Copy summary", "Download CSV" and "Print summary" let you share the accounts. "Create share link" puts the whole group in the web address after the # sign, a part browsers never send to the server. Keep in mind that anyone who receives the link can see the names and expenses.

FAQ

What if someone forgets an expense after paying people back?

Just add it. Repayments already marked as paid still count, and the tool lists the transfers that are still missing.

How do the others get the group?

Send them the share link. Opening it loads the full group and saves it on their device too. Changes do not sync, so send a fresh link after each update.

Can I change an expense after entering it?

Yes, with the "Edit" button under the expense.

Does the CSV open in a spreadsheet?

Yes: one row per expense or repayment, one column per participant, comma separated.