How to prorate rent when a tenant moves out mid-month

A tenant gives notice on the 12th, the notice period runs 30 days, and the tenancy ends on the 11th of the following month. Now you owe a number that the lease never states outright. The term for it is prorated rent, the fraction of a full month's rent that covers only the days the tenant actually holds the unit. Getting the final month wrong is more expensive than getting the first month wrong, because by then the tenant has already paid you money and the argument is about a refund rather than a charge.

The last month is a different problem from any other month

Every other month is a flat charge. The final month combines three moving parts: the date the tenancy legally ends, the amount already sitting in your account, and the deposit accounting that follows. Those three get tangled when a landlord nets the rent refund against damage charges and sends one lump number. Keep them separate. Calculate the final rent owed, compare it with what the tenant already paid, and treat any overpayment as its own line item. Deposit deadlines are separate deadlines, and states enforce them separately. California, for example, requires the itemized deposit statement and any refund no later than 21 calendar days after the tenant vacates, while Vermont sets 14 days.

Fix the day count before you touch a calculator

Two numbers drive everything: how many days of the month the tenant is responsible for, and what you divide the rent by. Read the lease first. Some leases state the proration method outright, and if yours does, that clause controls and the argument is over. If the lease is silent, choose one method, write it into your final statement, and use the same method for every tenant so nobody can point to inconsistent treatment. The day count itself follows from the termination date. If the tenancy ends on the 14th, the tenant is responsible for 14 days, including the 14th, because possession runs through the end of that day. Do not count the day after the tenant hands back keys.

Method one: Actual days in that specific month

Divide the monthly rent by the number of days in the month the tenant is leaving, then multiply by the days occupied. Rent of $1,800 in August, which has 31 days, gives a daily rate of $58.06. Fourteen days of occupancy comes to $812.90. This method is the most defensible one, because the divisor matches the month being charged and a tenant can verify it on a calendar in ten seconds. Its quirk is that the daily rate changes month to month, so February costs more per day than August at the same monthly rent. Nobody notices until a February move-out, and then somebody notices.

Method two: The flat 30 day month

Divide the monthly rent by 30 no matter what month it is, then multiply by days occupied. That same $1,800 rent gives a daily rate of $60, and 14 days comes to $840, which is $27.10 more than the actual days method produced for August. Flip the calendar and the advantage flips. With rent of $2,100 and a February 12 move-out, actual days gives $75 per day and $900 owed, while the 30 day method gives $70 per day and $840 owed. A third variation divides annual rent by 365 for a fixed daily rate, which some property managers prefer because it never changes. All three are common. None of them is a state requirement in most places, and the one you cannot defend is the one you switch to only when it favors you.

Notice timing decides whether a partial month happens at all

Proration on the way out is usually a side effect of notice rules. Many states require notice for a month to month tenancy measured in days, which frequently produces a termination date in the middle of a rental period. California requires 30 days of notice from a tenant, with 30 or 60 days from an owner depending on how long the tenant has lived there, so a notice given on the 12th commonly lands the end date mid-month. Other states require the notice period to expire at the end of a rental period, which eliminates the partial month entirely and means full rent is due for the final month. Check your own state before assuming a prorated final month is even correct, because charging a partial month when the tenancy legally ran to month end leaves rent on the table.

When the fixed term itself ends mid-cycle

A 12 month lease that started on the 15th ends on the 14th, so the last month was never a full month to begin with. Two clean options exist. You can prorate the final month using whichever method the lease specifies, or you can prorate the first month and charge full rent for each month afterward, in which case the last partial month is already paid for and nothing is owed at the end. Pick one when the lease is drafted and say so in the rent clause. The failure mode is prorating both ends by accident, which means one partial month gets charged twice, or prorating neither, which means the tenant pays for days that fall outside the term.

Holdovers, early departures, and the days in between

A tenant who leaves early does not automatically stop owing rent. If the tenant vacates on the 10th but the notice period runs to the 25th, rent is owed through the 25th in most states, subject to any duty to mitigate that applies when you re-rent sooner. A tenant who stays past the termination date is a different situation, and a holdover clause charging a higher daily rate is enforceable in many states only if the amount bears some relation to actual loss. Either way, the honest calculation starts with the last day the tenant was legally entitled to possession, not the day the truck pulled away. Our prorated rent calculator handles the arithmetic once you have settled that date.

The final statement, and the refund you probably owe

Most move-outs involve a tenant who already paid the full month before the end date was set. Say rent is $1,800, the tenant paid all of it on August 1, and the tenancy ended August 14. Under the actual days method the tenant owed $812.90, so you owe $987.10 back. Send that with a plain statement showing the monthly rent, the method, the divisor, the days charged, the amount owed, the amount paid, and the difference. Then handle the deposit under your state's separate rules and deadline. If unpaid rent from earlier in the tenancy is in play, list it as its own line rather than folding it into the proration, and check your late fee terms against our late fee calculator before adding anything. Six lines of arithmetic on paper prevents most final month disputes from ever starting.

Sources

• California Civil Code section 1946.1, notice to terminate a tenancy
• California Civil Code section 1950.5, security deposit accounting
• 9 V.S.A. section 4461, Vermont security deposits
• California Department of Real Estate, Landlord Tenant Guidebook