Free tool
Prorated rent calculator
Move-in or move-out mid-month? Enter the rent and the date and get the prorated amount, by actual days in the month or the 30-day method, with the arithmetic shown so you can put it in the lease.
Educational calculator, not legal advice. A few jurisdictions regulate proration method or rounding; your lease language controls. Nothing you type here is stored.
How prorated rent is calculated
One formula: prorated rent = daily rate × days occupied. The methods differ only in how they get the daily rate.
| Method | Daily rate | $2,400 rent, June 20 move-in (11 days) | When it is used |
|---|---|---|---|
| Actual days in the month | Rent ÷ 28, 29, 30 or 31 | $80.00 × 11 = $880.00 | The default when the lease is silent. The calculator's first option. |
| 30-day month (banker's month) | Rent ÷ 30, every month | $80.00 × 11 = $880.00 | When the lease names it. The name comes from the 30/360 day count used on loans. The calculator's second option. |
| Yearly daily rate | Rent × 12 ÷ 365 (366 in a leap year) | $78.90 × 11 = $867.95 | When a lease wants one daily rate all year. Not in the calculator, so multiply it out by hand. |
June has 30 days, so the first two agree there. They split in every other month: the 30-day month overcharges in 31-day months and undercharges in February, and the yearly rate runs below actual days in 28- and 30-day months and above it in 31-day months. Whichever you pick, write it into the lease so nobody argues at move-out. If the lease is silent, use actual days. A tenant can check it against a calendar, and it never bills a day the month does not have.
Worked example: a move-in and a move-out
Rent is $2,400. The tenant moves in on June 20, 2026 and leaves on July 18, 2027.
Move-in. June has 30 days, and the tenant occupies June 20 through 30, which is 11 days: $2,400 ÷ 30 = $80.00 per day → $80.00 × 11 days = $880.00.
Move-out. July has 31 days, and the tenant pays through the 18th, which is 18 days: $2,400 ÷ 31 = $77.42 per day → × 18 days = $1,393.55 by actual days, or $80.00 × 18 = $1,440.00 by the 30-day method. The calculator carries the unrounded daily rate, which is why $77.42 × 18 shows as $1,393.55 and not $1,393.56.
Same rent, but a July 20 move-in: $2,400 ÷ 31 = $77.42 per day × 12 days = $929.03 by actual days, versus $880.00 by the 30-day method. That $49 gap is the whole methods debate.
February and leap years
February is where the methods drift furthest apart. A $2,400 rent with a move-in on February 20:
| Year | Actual days | 30-day month | Yearly daily rate |
|---|---|---|---|
| 2026 (28 days) | $85.71 × 9 days = $771.43 | $80.00 × 11 days = $880.00 | $78.90 × 9 days = $710.14 |
| 2028 (29 days, leap year) | $82.76 × 10 days = $827.59 | $80.00 × 11 days = $880.00 | $78.69 × 10 days = $786.89 |
The 30-day method treats every month as 30 days long, so a February 20 move-in owes 11 days, the 20th through a notional 30th. That is the 30/360 convention and it is how the calculator counts: $108.57 more than actual days in 2026 and $52.41 more in 2028. A February 10 move-out owes 10 days either way, $857.14 by actual days in 2026 or $800.00 by the 30-day month.
Three edge cases to settle before you run the numbers:
- Leaving on the last day of the month is a full month. Charge the full rent. The 30-day setting reads a February 28 move-out as 28 of 30 days, $2,240.00 on $2,400, so do not run a full February through it.
- Moving in on the 31st owes 1 day under both methods: $77.42 by actual days, or $80.00 by the 30-day month, which counts the 31st as the 30th. A move-out on the 31st under the 30-day month owes 30 days, the full rent.
- Moving in on the 1st owes the full month. There is nothing to prorate.
Daily rent rate by month length
With the actual-days method the daily rate moves with the calendar, so the same rent costs more per day in February than in July. Here is the rate at three common rents:
| Days in the month | $1,800 rent | $2,400 rent | $3,000 rent |
|---|---|---|---|
| 28 (February) | $64.29 | $85.71 | $107.14 |
| 29 (leap-year February) | $62.07 | $82.76 | $103.45 |
| 30 (Apr, Jun, Sep, Nov) | $60.00 | $80.00 | $100.00 |
| 31 (Jan, Mar, May, Jul, Aug, Oct, Dec) | $58.06 | $77.42 | $96.77 |
| 30-day method (any month) | $60.00 | $80.00 | $100.00 |
Multiply the daily rate by the days occupied and you have the prorated amount. The calculator above runs the same arithmetic for any rent and any date.
When the prorated month is usually paid
Standard practice protects the landlord: collect a full first month's rent plus the deposit at signing, then apply the prorated amount to the second month. A tenant who moves in on the 20th pays the full month upfront and a small second-month bill, instead of starting the tenancy on a $880 payment. It also keeps the rent due date on the 1st from day one.
Move-in vs move-out: which days count
The standard convention, and the one the calculator uses, counts both ends of the stay:
- Move-in: the move-in day is a day the tenant occupies. The 20th of a 30-day month owes 11 days, not 10.
- Move-out: the tenant pays through the move-out date. Leaving June 11 owes 11 days.
- In and out in the same month: count from the move-in day through the move-out day. June 5 to June 20 is 16 days, $2,400 × 16 ÷ 30 = $1,280.00. The calculator takes one date at a time, so do this one by hand.
Where move-out proration gets messy is when notice periods and lease end dates disagree; the lease's holdover and notice clauses control, and the deposit is not a substitute for the last month's prorated rent unless the lease says so. Track what was actually owed and received per tenancy in a rent ledger, and the move-out reconciliation writes itself.
Prorating other charges
The same daily-rate math prorates anything billed by the month: a flat utility fee, pet rent, parking, or a landlord-paid bill you pass through mid-cycle. Divide the monthly amount by the days in the period, multiply by the days that apply, and note the method on the invoice or in the lease the same way you would for rent.
Prorated rent chart: what share of the month a move-in day costs
The table above fixes the rent and moves the calendar. This one does the opposite: it fixes nothing, so it works for any rent. Find the move-in day, take the share for that month length, and multiply it by your monthly rent. Days owed counts the move-in day itself, which is the convention almost every lease uses.
| Move-in day | Days owed in a 30-day month | Share of the rent | Days owed in a 31-day month | Share of the rent |
|---|---|---|---|---|
| 1st | 30 | 100.00% | 31 | 100.00% |
| 5th | 26 | 86.67% | 27 | 87.10% |
| 10th | 21 | 70.00% | 22 | 70.97% |
| 15th | 16 | 53.33% | 17 | 54.84% |
| 16th | 15 | 50.00% | 16 | 51.61% |
| 20th | 11 | 36.67% | 12 | 38.71% |
| 25th | 6 | 20.00% | 7 | 22.58% |
| 28th | 3 | 10.00% | 4 | 12.90% |
| 30th | 1 | 3.33% | 2 | 6.45% |
Two things fall out of it. A move-in on the 16th of a 30-day month is exactly half the rent, which is where the "half month" rule of thumb comes from; in a 31-day month the same date is 51.61%, so the shortcut quietly undercharges. And the shares are not symmetrical, because the move-in day is a day the tenant occupies: the 20th of a 30-day month leaves 11 days, not 10.
Round the dollars, not the percentage. The shares above are shown to two decimals for reading, so the exact arithmetic is still rent multiplied by days, divided by days in the month. The page's own example, $2,400 with a June 20 move-in, is $2,400 x 11 / 30 = $880.00 exactly, where 36.67% x $2,400 gives $880.08. Eight cents is nothing until a tenant checks your math.
Prorated months and Schedule E fair rental days
A prorated month shows up twice at tax time. The dollars are simple: prorated rent is ordinary rental income, reported on Schedule E line 3 in the year you receive it. The days matter too. Schedule E asks for fair rental days per property, and in a move-in month only the days the tenant actually rented count, 11 days for a June 20 move-in, not 30. Days the unit sat vacant between tenants are not fair rental days, though expenses for a unit held out for rent stay deductible while it sits empty. If you tally this by hand, the Schedule E worksheet keeps the income and the day counts in one place.
How I handle a prorated month in Oberlin24
I run two rentals of my own. By hand, a partial month is the arithmetic above plus a line in the rent ledger. In Oberlin24 the same proration engine sits behind this page, the rent roll and the assistant, so all three give the same figure to the cent:
- The rent roll expects the actual-days figure in a lease's move-in month and labels the row "first month prorated," so a correct $880.00 first payment reads paid instead of partial. An ended lease's last month is billed through the move-out date and labeled "last month prorated." A lease still active past its end date is a holdover and expects the full month.
- A move-in payment that equals the deposit plus a prorated first month, by either method within $5, goes to review with a note that splits it, so the deposit stays off Schedule E.
- The assistant answers "she moves in on the 20th, what does she owe" by reading the rent off her lease and returning the daily rate, the days and the amount, by actual days unless I ask for the 30-day month.
You can click through the rent roll in the live demo. This page and a spreadsheet will do the same job, it is 2026 and the tools are cheap. What matters is that the partial month gets booked as rent, on its own line, with the method written down.