π Prorated Rent Calculator
The exact fair rent for any partial month.
Prorated rent owed
Estimates for planning only, not financial advice.
Prorated rent is the fair share of a monthβs rent when you move in or out mid-month. Divide the monthly rent by the number of days in that month, then multiply by the days you actually occupy the unit. Moving into an $1,800 apartment on the 12th of a 30-day month means 19 days at $60 a day, or $1,140.
Landlords and tenants argue about this less than almost any other money topic, because the math is clean and both sides can check it. The only real decisions are which day counts as day one and whether to use the actual days in the month or a flat 30. This calculator uses actual days, the most common lease method.
How to Use This Calculator
Enter the full monthly rent, the day of the month the tenancy starts (or the last day it covers for a move-out), and how many days are in that month. The calculator counts the start day as an occupied day, which matches standard practice.
Enter the monthly rent exactly as written in the lease.
Enter the move-in day, or for a move-out the last day you hold the keys.
Set the days in the month: 28, 29, 30, or 31. February prorations use 28 or 29.
Collect or pay the prorated total. Keep the math with the lease so nobody re-argues it later.
The Prorated Rent Formula
Prorated rent = daily rate x days occupied
Days occupied includes the move-in day. Move in on the 12th of a 30-day month and you occupy the 12th through the 30th: 19 days. Some leases instead use a flat 30-day divisor every month, which slightly favors the tenant in February and the landlord in 31-day months. Actual days is fairer and far more common.
A few states and large property managers use a yearly method: annual rent divided by 365 times days occupied. On a 30-day month the difference is a few dollars either way. If your lease names a method, follow the lease; the lease wins over any calculator.
Worked Example
Rent is $1,800, move-in is the 12th, and the month has 30 days. Daily rate = $1,800 / 30 = $60. Days occupied = 30 - 12 + 1 = 19. Prorated rent = $60 x 19 = $1,140. The tenant pays $1,140 for the partial month, then the full $1,800 on the first of the next month.
Move-out version: same rent, tenant leaves on the 20th of a 31-day month and returns the keys that day. Daily rate = $1,800 / 31 = $58.06. Days occupied = 20. Prorated = $58.06 x 20 = $1,161.29. If the tenant already paid the full month, the refund is $1,800 - $1,161.29 = $638.71.
Move-In Day Rules Worth Knowing
| Situation | How to count it |
|---|---|
| Move in on the 1st | Full month, no proration needed |
| Move in mid-month | Count the move-in day as day one |
| Move out mid-month | Count through the day keys are returned |
| February | Use 28 days, or 29 in a leap year |
| Lease signed but keys later | Proration starts when you get possession, not when you sign |
Get the start date in writing before money changes hands. Most proration disputes are not about the math, they are about whether the tenancy started on the 12th or the 15th. A dated email confirming key handover ends that argument permanently.
Prorated Rent and Your Budget
A partial first month is the cheapest month of a tenancy, which makes it tempting to spend the savings. Keep it. Between the security deposit, movers, and utility setup fees, move-in month is usually the most expensive month overall despite the prorated rent. Run the full move-in cost through our 50/30/20 budget planner before the boxes arrive.
Renters comparing two apartments with different move-in dates should compare total first-year cost, not monthly rent alone. A $1,800 unit available on the 12th costs $1,140 + 11 x $1,800 = $20,940 for the first 12 months of tenancy, while a $1,750 unit available on the 1st costs $21,000. The cheaper monthly rent loses by $60 once proration is counted. Our rent affordability calculator keeps the monthly budget honest after that.
Deposits, Last Month, and Proration Together
Proration applies to rent, not to the security deposit. The deposit is almost always a full month or a fixed legal amount regardless of move-in date, and it sits untouched until move-out. Last-monthβs rent, where collected, is also a full month. So a mid-month move-in often means paying prorated first-month rent plus a full deposit plus possibly full last-month rent on day one: the cheapest rent month can still be the most expensive move-in month.
On move-out, the same separation applies. Prorated final rent covers the occupied days; the deposit is refunded separately, minus documented damages, usually within 14 to 30 days depending on the state. Tenants should photograph the unit at move-in and move-out with timestamps, because deposit disputes are fought on evidence, not memory. And never let a landlord apply the deposit to the last monthβs rent without written agreement: in many states that reclassifies the money and changes everyoneβs rights.
Proration and Renters Insurance Timing
Start renters insurance on the move-in day, not the first of the next full month. The prorated period is still a tenancy: your belongings are in the unit and your liability has begun. A $15 monthly policy costs pennies per day, and a gap during the move, when boxes pile in hallways and strangers help carry, is exactly when claims happen. Set the policy start date to the key-handover date.
Landlords should document the proration in a written addendum, not a text message. State the monthly rent, the daily rate, the days counted, and the total due, with both signatures. When the tenant later disputes the first monthβs charges, and some will, the signed addendum ends the conversation in one email. Five minutes of paperwork at move-in saves hours of argument at move-out. Professionalism is mostly just writing things down.
Estimates for planning only, not financial advice.
Frequently Asked Questions
How do you calculate prorated rent?
Divide the monthly rent by the number of days in the month to get the daily rate, then multiply by the number of days you occupy the unit, counting the move-in day. For $1,800 rent moving in on the 12th of a 30-day month: $60 per day x 19 days = $1,140.
Do you count the move-in day?
Yes, standard practice counts the move-in day as an occupied day. Moving in on the 12th means you pay for the 12th through the last day of the month.
Should I use 30 days or actual days in the month?
Actual days is the most common and fairest method. A flat 30-day divisor is simpler but overcharges slightly in February and undercharges in 31-day months. Follow whatever method your lease specifies.
How is prorated rent handled on move-out?
The same math in reverse: daily rate times days through key return. If you prepaid the full month, the landlord refunds the unoccupied days. Get the key-return date in writing.
What about February?
Use 28 days, or 29 in a leap year. The daily rate is higher in February, which surprises some tenants, but it is the correct actual-days math.
Can a landlord charge a full month for a partial month?
Only if the lease says so and state law allows it. Most leases prorate, and many states require it. Read the lease before paying.
Does prorated rent apply to the security deposit?
No. The security deposit is almost always a full monthβs rent (or a fixed amount set by law) regardless of the move-in date. Proration applies to rent only.
What if my lease uses a different method?
The lease controls. Some leases use annual rent divided by 365, or a flat 30-day month. Run the leaseβs method; the difference from actual-days math is usually a few dollars.
Is prorated rent taxed differently?
No. It is rental income or housing cost like any rent payment. Keep records the same way you would for full months.
Can I negotiate the move-in date to save money?
Moving in a few days later in a long month barely changes the math, but shifting into a short month or negotiating a free partial week can. The bigger lever is usually the monthly rent itself, not the proration.