Prorated Rent Calculator (Tenant Move-In & Move-Out Math by State)

You sign a lease that starts on the 18th, and the leasing agent asks for “the prorated amount” before handing over the keys. How much is that, exactly? Prorated rent is the part of a month’s rent you actually owe when you move in or out partway through the billing period. It sounds simple, and the math is, but there are three accepted ways to do it, and they can land a few dollars apart on the same move. This calculator runs all three so you can see the difference and match whichever one your lease names.

What prorated rent actually means

A lease bills you for a whole month at a time, usually the 1st through the last day. Proration means splitting that monthly figure down to the days you actually use when the month is partial. Move in on the 18th and you did not occupy the unit for the first 17 days, so you should not pay for them. The same logic runs in reverse when you leave mid-month: You owe through your move-out day and nothing after.

The building block for every method is the daily rate, which is what one day of rent costs. Multiply that daily rate by the number of days you occupy and you have your prorated rent. Everything else on this page is about how you arrive at that daily rate, because there is more than one accepted way to do it.

The three ways to calculate prorated rent

Most disputes over prorated rent are not about the day count. They happen because the tenant used one method and the landlord used another. Here are the three you will run into, using a $1,500 rent and a move-in on the 18th of a 30-day month (13 days occupied) so you can compare them side by side.

In a 30-day month the actual-days and banker’s-month methods match. The gap shows up in 31-day months and in February. The actual-days method divides by the real length of the month, so it is the most calendar-accurate and the one most landlords and courts treat as reasonable. The banker’s month always divides by 30, which slightly overcharges in a 31-day month and undercharges in February. The 365-day method finds a true average daily rate across the year and is most common in commercial leases. None of them is “wrong,” but your lease should name one, and you should use the same one your landlord does.

How to calculate prorated rent step by step

Whichever method your lease uses, the steps are the same. Here is the actual-days version, which is the safe default if the lease is silent.

1. Find the days in your month. Check a calendar for that exact month: 28 days (29 in a leap year like 2028), 30, or 31.
2. Count the days you occupy. For a move-in, count from your move-in day through the last day of the month, including the move-in day. For a move-out, count from the 1st through your move-out day, including that day.
3. Divide rent by days in the month to get the daily rate.
4. Multiply the daily rate by the days you occupy. That is your prorated rent.

Move-in vs. Move-out: Same math, Opposite direction

Proration works the same way coming and going. The only thing that changes is which days you count.

• Moving in (partial first month): You occupy from your move-in day through the end of the month. In a 31-day month, moving in on the 18th means 14 days (the 18th through the 31st).
• Moving out (partial last month): You occupy from the 1st through your move-out day. Leaving on the 12th means you owe 12 days, even if you hand back the keys early in the morning, because you held the unit that day.

A common move-out point of confusion: Prorated rent is separate from your security deposit. You prorate the final month’s rent for the days you stayed, and the deposit is settled on its own timeline (in Texas, for instance, a landlord must return the deposit within 30 days under state landlord-tenant law, Tex. Prop. Code § 92.103). Do not let a landlord roll a “cleaning fee” or last-month charge into the prorated figure; proration is only about days occupied.

Is a landlord required to prorate rent?

This is where a lot of online guides get it wrong, so here is the accurate version. In most states there is no law that forces a landlord to prorate rent or that dictates a formula. Proration is governed by your lease and by local custom. If the lease is silent, courts generally expect a reasonable charge for a partial month, which in practice means the actual-days calculation.

You will see articles citing California statutes like “Civil Code § 1941.1” or “§ 1947” as proration requirements. They are not. Section 1941.1 covers a landlord’s duty to keep a unit habitable, and Section 1947 covers when rent is due, not how to split a partial month. There is no California statute that sets a proration formula. Treat any source that cites one as a red flag, and rely on your lease instead.

A few places do lean harder on the daily-rate method. New York’s housing agency applies actual-day calculations to rent-stabilized units (apartments whose rent increases are capped by law) when a dispute reaches it, and cities such as Chicago expect “fair” proration as a matter of practice. Even there, the rule is the daily-rate result, not a different formula.

Prorated rent by state: What actually governs it

Because proration is contract-driven, the honest state-by-state picture is less about statutes and more about what controls when the lease is unclear. Here is how it shakes out in the states people ask about most.

The takeaway is the same everywhere: Read your lease for the method, and if it does not name one, use the actual-days calculation and keep a written record of how you got the number. If your tenancy is month-to-month, the proration question usually comes up at the very start and the very end, so it is worth settling it in your month-to-month rental agreement.

Five prorated rent mistakes to avoid

• Dividing by 30 in a 31-day month without lease support. The banker’s-month shortcut quietly overcharges in long months. If your lease does not specify it, use actual days.
• Forgetting February’s real length. February has 28 days, or 29 in a leap year (the next is 2028). Using 28 in a leap year overcharges the tenant; the calculator above handles this from the date automatically.
• Skipping the move day. The day you take possession or return the keys is a day you occupied. Leaving it out shorts the count by one day.
• Letting late fees attach to a prorated amount. A partial first month is still rent. If it is paid on time, no late fee applies; check your grace period and how a rent change or fee is documented.
• Prorating utilities the wrong way. If your lease splits utilities by occupancy, prorate them on the same day count, not the full month.

Put the method in writing

The cleanest way to avoid a proration argument is to write the agreed number and method into the lease before anyone moves. A solid residential lease should state the prorated first-month amount, the method used, and the due date. If you are drafting or updating a lease, a guided builder makes this straightforward.

Drafting a lease and want the prorated first month spelled out correctly? LawDepot’s residential lease builder walks you through the rent, proration, and due-date clauses step by step.

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If you are a landlord handling several move-ins a year, doing this by hand gets tedious and error-prone. Property-management platforms such as DoorLoop prorate the first month automatically when you set up a new tenant and then collect it online, which removes the manual math entirely. Running the numbers on a single rental first? The property management fee & ROI calculator and the rent-to-own calculator cover the other money questions that come up at lease signing.

Frequently Asked Questions

How do I calculate prorated rent?

Take your monthly rent, divide it by the number of days in that month to get the daily rate, then multiply by the days you occupy. For example, $1,500 rent in a 30-day month is a $50 daily rate, so 13 days of occupancy is $650. The calculator above does this for all three methods at once.

Should I divide by 30 or by the actual days in the month?

Use whichever your lease names. If the lease is silent, the actual-days method (divide by the real length of the month) is the most common and the one courts generally treat as reasonable. The flat 30-day “banker’s month” is also used, but it overcharges slightly in 31-day months.

Is a landlord required to prorate rent?

In most states, no. There is no law forcing proration or setting a formula, so the lease controls. A landlord may agree to prorate to fill a vacancy sooner or to be fair, and rent-stabilized units in New York are handled on a daily-rate basis. If you want proration, get it in writing before you sign.

Do you count the move-in or move-out day?

Yes. The day you take possession or return the keys counts as a day you occupied the unit. For a move-in, count from your move-in day to the end of the month; for a move-out, count from the 1st through your move-out day.

How does proration work in February or a leap year?

Use the actual number of days in that February: 28 in a normal year, 29 in a leap year (the next is 2028). The shorter the month, the higher the daily rate under the actual-days method, so February days cost a little more than days in a 31-day month at the same rent.

Can a landlord charge a full month if I move in mid-month?

If the lease allows it and no local rule says otherwise, it is possible, but most landlords prorate because charging full rent for days you did not occupy is a frequent source of disputes. If the lease is silent, ask for proration and confirm the amount in writing before you pay.

Is prorated rent taxable or refundable?

Prorated rent is ordinary rent for the days you occupy, so it is treated like any other rent payment. It is not a deposit and is not separately refundable; if you move out mid-month, you owe through your move-out day rather than the full month.

Elena Rodriguez

Elena Rodriguez writes about real estate and landlord-tenant law for ClearLegalTips. She focuses on making leases, security deposits, and rental rules understandable for tenants and small landlords handling them without a lawyer.