Three ways to prorate rent
Days in month: Rent ÷ Days in that month × Days occupied
365-day year: Rent × 12 ÷ 365 × Days occupied
Banker’s month: Rent ÷ 30 × Days occupied
365-day year: Rent × 12 ÷ 365 × Days occupied
Banker’s month: Rent ÷ 30 × Days occupied
Example: Rent is $1,500 and you move in on October 18, 2026, so you occupy 14 of October’s 31 days. By the days-in-month method you pay $677.42 ($48.39 a day). With the 365-day method it is $690.41 ($49.32 a day), and with the 30-day method $700.00 ($50.00 a day).
Tips for tenants and landlords
- Write the proration method and amount into the lease or move-in letter.
- Some landlords collect a full first month and prorate the second — the total is the same.
- For the security deposit and last month’s rent, proration normally does not apply.
Count the exact days between two dates with the date difference calculator.
Frequently asked questions
How do I calculate prorated rent?
Find the daily rent and multiply it by the days you occupy the unit. The most common method divides the monthly rent by the days in that month: $1,500 ÷ 31 days × 14 days = $677.42 for a move-in on October 18.
Which proration method is correct?
Whatever your lease says. Days-in-month is most common. Some landlords use an annual daily rate (rent × 12 ÷ 365), which gives the same rate every month, and some use a 30-day “banker’s” month.
Is the move-in day counted?
Usually yes: if you get the keys on the 18th, you pay from the 18th through the end of the month. For move-out, the move-out day is normally included too.
Do landlords have to prorate rent?
In most U.S. states it is not required by law for move-in — it is agreed in the lease. If you give proper notice and move out mid-month, many leases still require rent for the full notice period.