Shared Willow

Rent split, chore charts & shared expenses

Shared expenses settle-up

Log who paid for the shopping, the bills and the takeaway. The calculator keeps everyone's balance and works out the fewest payments to make it square.

People

  • Ana
  • Ben
  • Cy
  • Dee

Add an expense

Split

Settle up

  1. DeepaysBen£47.51
  2. CypaysAna£39.89
  3. DeepaysAna£6.98

3 payments for 4 people with a balance: the fewest possible.

Balances

  • Anais owed £46.87paid £119.37, share £72.50
  • Benis owed £47.51paid £120.00, share £72.49
  • Cyowes £39.89paid £18.60, share £58.49
  • Deeowes £54.49paid £42.00, share £96.49

Expenses

  • Big shop at the marketAna paid · split equally between everyone
    £84.37
  • Electricity, OctoberBen paid · by shares: Ana 1, Ben 1, Cy 1, Dee 2
    £120.00
  • Cleaning suppliesCy paid · split equally between everyone
    £18.60
  • Pizza nightDee paid · split equally: Ana, Ben, Dee
    £42.00
  • New kettleAna paid · exact amounts: Ana £8.75, Ben £8.75, Cy £8.75, Dee £8.75
    £35.00

5 expenses · £299.97 in all

How to use it

  1. Add everyone in the house (or on the trip), then each shared expense: what it was, the amount and who paid.
  2. Choose how it is shared. Equally between the people you tick; by shares when someone uses more (2 shares pays twice as much as 1); or exact amounts that must add up to the total.
  3. Read the payments under Settle up. Copy them into your group chat; once paid, start a new group or clear the old expenses.

How the fewest payments are found

Each person's balance is what they paid minus their share. Balances always add up to zero, so a group of n people with a balance can always settle in n − 1 payments: the simple greedy rule (the person who owes most pays the person owed most, then repeat) does exactly that. It is fast but not always the shortest. If the group splits into smaller sets whose balances cancel out on their own, each set can settle separately and one payment is saved per set. For groups of up to 16 people with a balance, the calculator checks every possible set to find the most that cancel, which gives the fewest payments possible. Bigger groups fall back to the greedy rule.

Cents add up

Amounts are kept in whole cents. When a bill does not divide evenly, the leftover cents go one each to the people with the largest remainders, so the shares always equal the bill.

Questions

Where is my group saved?

In this browser's local storage, including names and amounts. Nothing is uploaded, so the group is only on this device; use Copy summary to share it.

What if someone paid for only part of a bill?

Enter each payment as its own expense with the same split. The balances combine them.

Does it handle different currencies?

One currency per group. For a trip, convert to one currency before adding expenses.