Why show two methods?
The arithmetic is simple; the applicable method is not always universal.
A property can describe proration differently in a lease, move-in quote or billing policy. Comparing both formulas helps you spot the size of the difference without pretending that one formula automatically controls every tenancy.
Before relying on the result
- Confirm the monthly rent used for the partial period.
- Confirm the first and last billable day.
- Check whether the property uses actual days in the month, a fixed 30-day divisor or another written method.
- Separate prorated base rent from move-in fees, deposits and utilities.
Math tool only. RentBillCheck does not determine which proration method your landlord must use. Check the lease and the applicable state/local rule when the method is disputed.