How to Calculate Prorated Rent for Move-In & Move-Out (2026)

TL;DR: The Quick Answer

Prorated rent is a partial rent payment for a month you do not occupy the full time — when you move in or out mid-month. The formula is simple: (Monthly Rent ÷ Days in the Month) × Days Occupied = Prorated Rent. Example: $1,500 rent, move in on the 15th of a 30-day month: $1,500 ÷ 30 = $50/day × 16 days (the 15th through the 30th, inclusive) = $800. Most landlords prorate move-in rent automatically; move-out proration depends on your lease and your state’s notice rules. Use the free calculator below to get your exact number in seconds.

Free Prorated Rent Calculator

Use this tool below. Enter your monthly rent, choose move-in or move-out, pick the date, and select the calculation method your lease uses. The calculator handles leap years, 28/29/30/31-day months, and inclusive day counting automatically.

What Is Prorated Rent, Exactly?

Prorated rent is the fair-share portion of one month’s rent that covers only the days you actually live in a rental. If your lease starts on the 1st, you pay a full month. If it starts on the 10th, you should pay only for the 10th through the end of the month — not the full month. The same logic applies when you move out before the month ends. Zillow’s prorated rent calculator guide uses the same daily-rate method, and it is the standard across the rental industry.

Proration matters because rent is quoted as a monthly figure, but leases rarely line up perfectly with calendar months. Getting the math right matters for both sides: a tenant overcharged by even $50 a year across millions of households is real money, and a landlord who undercharges leaves revenue on the table. Most disputes come down to two details: which “days in the month” denominator the lease uses, and whether move-in/move-out day itself counts as a billable day.

When Does Prorated Rent Apply?

Prorated rent comes up in four common situations:

• Mid-month move-in: Your lease starts on any day other than the 1st. The first month’s rent is prorated; the second month is usually a full month due on the 1st.
• Mid-month move-out: Your lease or month-to-month tenancy ends before the last day of the month. You pay only through the termination date.
• Lease renewal on a non-1st date: Some landlords align renewal dates to the 1st with a partial month.
• Early lease termination: If you break a lease early, you may owe rent through the date the landlord re-rents the unit — which can involve proration, though you may also owe penalties.

Not every move-out is prorated. If you signed a 12-month lease and leave before it ends, the landlord can often hold you to the full remaining rent (or until they find a new tenant), regardless of which day you physically leave. Proration applies when the tenancy legally ends mid-month, not when you simply hand back the keys early.

The Prorated Rent Formula and 3 Calculation Methods

The core formula has two steps: turn the monthly rent into a daily rate, then multiply by the billable days. But the denominator you use for “daily rate” can vary, and that changes the answer slightly.

The actual days method is the most common and most defensible. April (30 days) and March (31 days) produce slightly different daily rates, which is logical because a day in a 30-day month is a larger fraction of the month. The flat 30-day method treats every month as 30 days — simpler, but it overcharges in 31-day months and undercharges in February. The yearly method converts annual rent to a daily rate; it is the most mathematically precise but rare in residential leases. Always check your lease: if it specifies a method, that method controls. If it is silent, most states default to actual calendar days.

Step-by-Step Calculation With Real Examples

Move-in example: Rent is $1,800. Lease starts September 18. September has 30 days.

• Daily rate: $1,800 ÷ 30 = $60.00
• Billable days: September 18 through September 30 = 13 days (count the 18th — move-in day is included)
• Prorated rent: $60 × 13 = $780

Move-out example: Rent is $2,100. Tenancy ends March 12. March has 31 days.

• Daily rate: $2,100 ÷ 31 = $67.74 (do not round the daily rate — round only the final answer)
• Billable days: March 1 through March 12 = 12 days (move-out day is included in most states)
• Prorated rent: $67.74 × 12 = $812.90

Two counting rules prevent most mistakes: for move-ins, count from move-in day through the last day of the month, inclusive. For move-outs, count from the 1st through your termination date, inclusive. When in doubt, count on a calendar with your finger — it is faster than mental math and catches off-by-one errors.

Move-In vs Move-Out: Why the Counting Differs

Move-in and move-out proration use the same formula but count days from opposite ends of the month. For a move-in on the 15th, you pay from the 15th to the 30th. For a move-out on the 15th, you pay from the 1st to the 15th. In both cases the day itself usually counts — you typically pay for the day you get the keys and the day you hand them back. Apartments.com’s guide to prorating rent confirms this inclusive-counting convention. Always confirm with your lease, because a few landlords count from the day after move-in, which shifts the total by one day.

The bigger move-out question is whether proration even applies. Most states require month-to-month tenants to give 30 days’ written notice; some require 60 or 90 days. If your notice period runs past the end of a month, your legal obligation to pay may extend to a full month even if you physically leave earlier. The termination date on the notice — not the moving-truck date — determines when rent stops.

State Laws and Lease Terms: What Controls

There is no federal law mandating proration. The rules come from your lease and your state’s landlord-tenant code. A few key points:

• California (Civil Code §1946): When a month-to-month tenancy ends, rent is owed only through the termination date — proration is required.
• New York City rent-stabilized units: Proration is specifically required by the Rent Stabilization Code.
• Texas, Florida, Colorado: No specific statutory method — your lease controls, and most landlords use the actual-days method.
• Notice periods: Most states require 30 days’ notice for month-to-month tenancies; California requires 60 days after one year of tenancy; Delaware requires 60 days; Washington tenants give 20 days. Give proper notice or you may owe a full extra month.

Landlord Studio’s complete guide to prorated rent recommends putting the proration method in writing in the lease — that is the single best way to avoid disputes later. If you are a tenant and the math looks off, ask for the calculation in writing; a landlord who cannot show you the daily rate and day count may have made an error.

Common Proration Mistakes to Avoid

• Rounding the daily rate early. Round only the final answer to the nearest penny. Rounding $1,800 ÷ 31 to $58.06 then multiplying can produce a result off by several dollars.
• Forgetting leap year. February has 29 days in leap years (2024, 2028). If you use the actual-days method, the daily rate is slightly lower in a leap-year February.
• Counting move-in day as free. Most landlords charge for move-in day. If you get the keys on the 15th, the 15th is billable.
• Assuming move-out is automatically prorated. It is only prorated if your tenancy legally ends mid-month. Breaking a lease early can cost you full months plus fees.
• Using the wrong denominator. If your lease says “30-day month,” using actual 31 days undercharges you by about 3%. Read the lease.

If you are weighing renting against buying, our mortgage calculator can show you what a comparable home payment would look like. And whether you rent or own, keep your security deposit and move-in funds in a high-yield savings account earning 4–5% until you need it.

Frequently Asked Questions

Final Verdict

Prorated rent is one of the simplest calculations in personal finance — and one of the most often messed up. Remember the formula, count days inclusively, check your lease for the denominator method, and always get the math in writing. Use the calculator above to double-check whatever your landlord quotes. A few minutes of verification can save you hundreds of dollars over a tenancy, and it keeps both sides honest. Renting is expensive enough already — pay only for the days you actually live there.