How the proration calculator works
Enter the bill, the period it covers, and each person's move-in and move-out dates. The calculator counts the days each person was there (inclusive of both dates, within the bill period), and splits the bill in proportion to those person-days. The shares add up to the bill.
A worked example
A $186 bill for March (31 days). Ana and Ben live there all month, and Cleo moves in on the 16th and stays 16 days. That is 31 + 31 + 16 = 78 person-days. Ana and Ben pay $73.92 each and Cleo pays $38.16.
Agree the rule first
Decide whether the move-in day and the move-out day count. This tool counts both. If you count only nights, enter the dates to match.
Related guide: Splitting utility bills when someone moves in mid-month
Frequently asked questions
Does this work for rent as well?
Yes, but many flats split rent by room instead. See the rent split calculator.
What if the bill covers several months?
Set the period start and end to cover them. Days are counted across the whole period.
Is anything stored?
No. Everything stays in your browser.