How the math works
Days count both the first night and the last night. October 12 through October 31 is 20 days, and October has 31 days.
actual: prorated = rent ÷ days_in_month × occupied_days
30-day: prorated = rent ÷ 30 × occupied_days
365-day: prorated = rent × 12 ÷ 365 × occupied_days
If the range crosses a month boundary, each month is calculated separately, then added. This is not legal advice; the lease or local rule wins. Amounts are not converted between currencies.
FAQ
Do I pay for the move-out day?
This tool treats both dates as inclusive nights of occupancy. If your landlord charges through the morning you leave, that is the same as last night = the day before you hand back keys. Adjust the last-night date to match the lease.
Why is the 30-day method different?
A 30-day month ignores that February has 28 days and October has 31. Daily rent is slightly higher in long months under the actual-days method, and slightly lower under 30-day.
How do I calculate prorated rent when moving in mid-month?
Enter your monthly rent, the first night you occupy the unit, and the last night. Pick actual days (most US leases), 30-day month, or 365-day year—whichever your lease specifies.
Which proration method do US apartments use?
Many US leases prorate by actual calendar days in the month. Corporate or property-management leases sometimes use a flat 30-day divisor. Always follow your signed lease.