Split expenses calculator
Enter who paid what and each person's share, and get who pays whom.
Enter the total each person paid for the group. Share weight 1 for everyone is an equal split; use incomes, days or rooms as weights for an unequal one. Names and amounts are examples and stay in this browser only.
What the number means
When several people pay for shared things, nobody ends up paying exactly their share. The balance is the gap: positive means you paid more than your share and are owed the difference, negative means you paid less and owe it. The sum of all balances is always zero, which is why a short list of payments can clear everything. The page is general: groceries for a household, a trip, a gift, a party, shared bills. For splitting a single rent, see the roommate rent split calculator; for a restaurant check with a tip, the tip calculator.
The method
Total = the sum of what everyone paid. Fair share of person i = total × weight i ÷ sum of weights. Balance = paid − fair share. Settle-up: while someone has a positive and someone a negative balance, the person with the most negative balance pays the person with the most positive balance the smaller of the two absolute amounts. All money is handled in whole cents; when the shares do not divide exactly, the extra cents go to the largest fractional parts, so the shares always add up to the total. The method is standard arithmetic and our own code; there is nothing to look up.
Worked example
Alex paid $120.00, Sam $45.00, Jordan $0.00; weights 1, 1 and 2. Total $165.00; weights add up to 4; shares $41.25, $41.25 and $82.50. Balances: Alex $78.75, Sam $3.75, Jordan $-82.50. Settle-up: Jordan pays Alex $78.75; Jordan pays Sam $3.75. After those payments every balance is zero. The numbers come from the same function as the calculator, and the tests apply random cases to it and check that all balances reach zero.
Limits of this method
The weights are your choice, and the page does not say that income, days or equal shares is the fair rule: agree it before you use the result. The list of payments is short but not always the shortest possible, as one of the questions below shows. The page treats each person's payments as a single total, so it cannot handle an item that only some of the group share. Finally, it does not know about money already repaid; enter only the expenses that are still open.
How do I split shared expenses fairly when people paid different amounts?
Add up everything paid, split it by each person's share weight, and compare with what each person actually paid. Example values: Alex paid $120.00 for groceries, Sam paid $45.00 for utilities and Jordan paid nothing; Jordan uses the place twice as much, so Jordan's weight is 2 and the others' are 1. The total is $165.00, split 1 : 1 : 2, so the fair shares are $41.25, $41.25 and $82.50. Alex is owed $78.75 and Sam $3.75; Jordan owes $82.50. Two payments settle it: Jordan pays Alex $78.75 and Jordan pays Sam $3.75. With equal weights Jordan would owe $55.00 instead.
What should I use as the share weight?
Whatever the group agrees is fair: the page does not decide that. Equal weights split evenly. Income can be used as a weight: with incomes of $6,000 and $3,000 a month, the weights 6000 and 3000 (or 2 and 1) make the higher earner pay two thirds, so for $900 paid by A, B owes $300.00. Days present can be the weights for a trip where people joined for different numbers of days, and rooms or square feet can be used for a shared home. A weight of 0 means a person does not share in the costs at all but can still have paid. For the rent split of a household, the roommate rent split calculator is made for that; this page is for any other expenses.
How does the 'who pays whom' list work?
For each person the balance is what they paid minus their fair share. People with a positive balance are owed money; people with a negative balance owe it. The page repeatedly takes the person who owes the most and the person who is owed the most, and has the first pay the second the smaller of the two amounts. One of them is then settled, and this goes on until every balance is zero. With n people that takes at most n − 1 payments, so a group of five never needs more than four transfers. The balances always sum to zero, and in whole cents each balance is exactly zero after the last payment.
Is this really the smallest possible number of payments?
Not always. The method guarantees at most n − 1 payments, but the smallest possible number can be lower when the group splits into smaller groups whose balances add up to zero on their own. Finding the true minimum is a hard problem in general, so the page uses the simple method. Here is a case: seven people with balances +$2, −$7, +$10, −$8, −$2, +$8 and −$3 (found by a brute-force search). The page lists 5 payments, while 4 would be enough: the first and fifth cancel out, the sixth and fourth cancel out, and the other three settle among themselves. The result is correct either way; it just may include one payment more than the theoretical minimum.
What happens with cents when the amount does not divide evenly?
The page works in whole cents so that the shares add up to the total exactly. When a split leaves a remainder, the leftover cents go to the people with the largest fractions. For example $10.00 paid by one person among three equal people gives shares of $3.34, $3.33 and $3.33, which sum to $10.00, and the payments are $3.33 and $3.33. Nobody is ever off by more than a cent.
Can it handle a bill where only some people took part?
Not in a single run: the weights apply to everything you enter as one pool. If a dinner involved only some of the group, run it separately with just those people, then enter what each person owes or paid from that run as part of the larger pool. For a restaurant check with a tip, the tip calculator splits the bill and gratuity.
Is anything sent or stored?
The names and amounts stay in your browser so that the list is there when you return; the page does not send them anywhere and does not ask for account details. The page also does not move money: it shows who should pay whom, and you settle by whatever method you use.
An arithmetic helper — not legal, tax or financial advice; it does not move money, and you and your group decide what is fair. No outside data are used. Related: the roommate rent split calculator, tip calculator, budget calculator, fuel cost calculator and subscription cost calculator. How we check our calculators.