Calendar-day assumption
This calculator uses the calendar-day method. Some leases use a 30-day convention, local rules or lease-specific terms, so the lease should control real charges.
Example
If monthly rent is 1,800, the month has 30 days and you are charged for 12 days, prorated rent is 1,800 / 30 x 12 = 720 before other move-in fees.
Common mistakes
Check whether the first and last day are both charged. Also confirm whether move-in fees, deposits and prepaid utilities are rent or separate charges.
Limitations
This is not legal advice. Lease terms, local tenant rules and billing practices can override a simple calendar-day calculation.
Last reviewed: 2026-05-17