Group Expense Splitter

Group trips and shared homes go wrong in the same way: five people pay for six things, nobody remembers who paid for the taxi, and the final settling-up turns into an argument. The solution is dull but reliable arithmetic. List each cost with who paid and who shared it, add up what each person paid and what they owe, and work out the fewest payments that make everyone even. This page does exactly that, in plain sentences, with no sign-up and no app.

Writing the lines

Write one line per cost: the payer’s name, the word paid, the amount and a short description, for example “Asha paid 1200 Hotel”. If only some people shared the cost, end the line with split: and their names, as in “Cara paid 600 Dinner split: Asha, Cara”. Without that, the cost is shared equally by everyone in the group. Names are matched without regard to capital letters, so “asha” and “Asha” are the same person. A line the page cannot read produces a message naming the line number.

A worked example

The sample has four lines: Asha paid 1,200 for the hotel, Ben paid 450 for a taxi, Cara paid 600 for a dinner shared by Asha and Cara only, and Ben paid 90 for snacks. The total is 2,340 for three people, an average of 780 each. Asha paid 1,200 and owes 880, so is owed 320. Ben paid 540 and owes 580, so owes 40. Cara paid 600 and owes 880, so owes 280. Two payments settle it: Cara pays Asha 280 and Ben pays Asha 40. The second sample, a flat share with a guest called Raj, has a total of 42,900 and settles with Raj paying Dev 13,700 and Mia paying Dev 9,500.

How the balances are worked out

Each cost is converted to cents. For a group of k people the share is the cost divided by k, rounded down, and the leftover cents, fewer than k of them, are handed out one at a time to the first people in alphabetical order. Then each person’s share is subtracted from what they paid. The balances therefore sum to exactly zero, and no cent appears or disappears. A positive balance means the group owes the person; a negative one means the person owes the group.

Settling up with few payments

The settle-up step repeatedly takes the person who owes the most and the person who is owed the most, and has the first pay the second as much as possible. Someone is then fully settled, and the process continues with the rest. With n people with non-zero balances it needs at most n − 1 payments. It is not guaranteed to find the absolute minimum in every contrived case, but for ordinary groups it gives a short, easy-to-follow list.

Edge cases

Costs paid in different currencies must be converted before you enter them. A zero or negative amount is rejected. If everyone has paid exactly their share, the settle-up table says that everyone is even. A person who appears only in the extra-people box takes part in every cost that has no split list, as Raj does in the second sample, so that person owes a share even though they paid nothing.

Limits

Only equal splitting is supported. For unequal shares, such as a person who ate half as much, enter that person’s portion as a separate line paid by the diner who covered it. Tips, tax and currency conversion are not handled. The lines stay in your browser and are saved on your device so they are still there next time.

Related tools

• Tip Calculator works out a restaurant tip before you enter the bill as a cost.
• Percentage Calculator helps when a cost is shared in proportions rather than equally.
• Checkbook Register keeps a running balance once the money has been settled.
• Net Worth Calculator adds up what you own and owe, including money still owed to you.