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How to Calculate Prorated Rent

Proration methods at a glance

Prorated rent answers a simple question: if you do not live in a home for a whole month, how much rent do you owe for the days you do live there? The answer depends on the method you use, the rent amount, the month, and the exact dates. This guide walks through each method step by step, with worked examples you can check by hand, so you can spot an error before you pay.

Step 1: Confirm the method in your lease

Before doing any arithmetic, find out which method applies. Your lease, move-in agreement, or landlord’s written statement should say whether proration uses actual days in the month, a fixed 30 days, or a 365-day year. If it does not say, ask in writing and keep the reply. Using the wrong method is the most common cause of a prorated-rent dispute, because the same dates can give different totals — for example, $1,800 rent for 16 days in October is $929.03 on actual days and $960.00 on a 30-day basis. Neither figure is universally “correct”; correctness depends on the method that applies to you.

Step 2: Count the days occupied

Count inclusively unless your agreement says otherwise. If you move in on 16 October, you occupy 16 October through 31 October — that is 16 days, not 15. If you move out on 10 November, check whether the move-out day itself counts; agreements differ, so confirm it rather than assuming. Write the start date, end date, and day count down, and check them against the calendar for that month. February is the usual trap: a 28-day February gives a higher daily rate than a 31-day month for the same rent, and a leap-year February has 29 days.

The three formulas

Actual-days method: monthly rent ÷ days in the month × days occupied. 30-day method: monthly rent ÷ 30 × days occupied. This gives the same daily rate every month, which some landlords prefer for simplicity, but it overstates rent in short months and understates it in long months compared with actual days. 365-day method: monthly rent × 12 ÷ 365 × days occupied. Useful when a tenancy spans months of different lengths or a lease defines rent annually.

Worked example 1 — actual days: $1,800 rent, move-in 16 October, 31 days in October, 16 days occupied. $1,800 ÷ 31 = $58.0645 per day; × 16 = $929.03. Worked example 2 — 30-day: same rent and days. $1,800 ÷ 30 = $60.00 per day; × 16 = $960.00. Worked example 3 — 365-day: $1,800 × 12 = $21,600 per year; ÷ 365 = $59.1781 per day; × 16 = $946.85. Notice how the three methods span more than $30 for the same tenancy — always state the method next to the figure.

Prorating a move-out, a partial month, and a rent change

A move-out works the same way in reverse: count the days occupied in the final month and apply the agreed method. If rent changes mid-month — for example, a renewal takes effect on the 15th — prorate each part separately at its own rent level and add the two amounts, rather than averaging the rents. If a tenant moves in mid-month and the landlord also charges a full month’s deposit, remember the deposit is separate from prorated rent; do not let a deposit figure be confused with the first month’s rent in the calculation.

Common mistakes

• Counting the move-in day as day zero, or counting both the move-in and move-out days when only one should count.
• Dividing by 30 in a month with 31 days without checking whether the lease actually uses the 30-day method.
• Forgetting a leap year in February, or using the wrong month’s day count altogether.
• Rounding too early: keep full precision until the final step, then round to cents.
• Accepting a prorated figure with no method, dates, or day count shown — ask for the working.

If you are a landlord, showing your working on the move-in statement prevents most disputes. If you are a tenant and the figure does not match your own calculation, send your working in writing, cite the lease clause, and ask for a corrected statement before the payment date if possible. Keep a copy of both calculations.

Worked example: moving in on the 5th

Rent is $2,000 and you move in on 5 October, a 31-day month. Days occupied are 5 October through 31 October inclusive, which is 27 days — count them on a calendar rather than subtracting 5 from 31 and forgetting the move-in day itself. On actual days: $2,000 ÷ 31 = $64.5161 per day, × 27 = $1,741.94. On the 30-day method: $2,000 ÷ 30 = $66.6667 per day, × 27 = $1,800.00. On the 365-day method: $2,000 × 12 ÷ 365 = $65.7534 per day, × 27 = $1,775.34. The three figures span $58.06, and all three are arithmetically correct under their own method. If a bill for this move-in shows $1,800, it is using the 30-day method; if it shows $1,741.94, it is using actual days. Neither bill is self-evidently wrong until you know which method the lease names.

Worked example: moving out on the 9th

Rent is $1,650 and you move out on 9 November, a 30-day month, occupying 1 to 9 November inclusive, which is 9 days. On actual days and on the 30-day method the answer is the same, because the month has 30 days: $1,650 ÷ 30 × 9 = $495.00. On the 365-day method it is slightly lower: $1,650 × 12 ÷ 365 = $54.2466 per day, × 9 = $488.22. This is the one case where two methods cannot be confused with each other, and it is a useful check: if a November bill for 9 days does not show $495.00 under either actual-days or 30-day wording, the day count or the rent figure is different from the one you used, and that difference is where to look first.

Worked example: rent changes mid-month

Rent rises from $1,800 to $1,950 on 15 October, a 31-day month. Do not average the two rents. Prorate each part separately and add them. Old rent, 1 to 14 October, is 14 days: $1,800 ÷ 31 × 14 = $812.90. New rent, 15 to 31 October, is 17 days: $1,950 ÷ 31 × 17 = $1,069.35. The month's total is $812.90 + $1,069.35 = $1,882.25. Averaging the rents to $1,875 and prorating the whole month would give a different and misleading figure, because the cheaper rent applied to fewer days than the more expensive rent. The same separate-parts rule applies to any mid-month change, including a rent reduction: each rent level is charged only for the days it was in force, and the statement should show both lines.

Worked example: a high-rent, long partial month

Rent is $2,600 and you occupy 22 days of a 31-day month. On actual days: $2,600 ÷ 31 × 22 = $1,845.16. On the 30-day method: $2,600 ÷ 30 × 22 = $1,906.67. On the 365-day method: $2,600 × 12 ÷ 365 × 22 = $1,880.55. The gap between methods grows with rent and with days occupied, so a high-rent, late-month move-out is where checking the method saves the most money.

February, leap years and keys handed over early or late

February is where day counts most often go wrong. At $1,450 rent, moving in on 20 February in a leap year means occupying 20 to 29 February inclusive, which is 10 days: $1,450 ÷ 29 × 10 = $500.00 exactly. In a non-leap year the same move-in date means 20 to 28 February, which is 9 days: $1,450 ÷ 28 × 9 = $466.07. Same rent, same move-in date, different year, $33.93 apart — and both are correct under actual days. Keys matter too. If keys are handed over on the 3rd but the lease start date is the 5th, confirm which date starts the count; if keys are returned a day late, confirm whether that extra day is charged. Do not assume possession and lease dates are the same date: write both dates down and ask which one the calculation uses. A one-day difference at $2,100 rent in a 31-day month is $67.74, so a single day is worth confirming.

A worksheet you can copy

Keep the completed worksheet with the lease and the payment receipt. If a later bill disagrees, you can point to the exact line that differs. Landlords can use the same worksheet as a move-in statement.

What a prorated calculation does not tell you

A prorated figure settles one thing only: how much rent is due for days occupied under one method. It does not tell you whether a deposit is also due, whether a late fee applies, whether a rent cap limits a later increase, or whether a city ordinance changes the result. For the verified state rules on caps, deposits and late fees, see Rent Rules Explained; for anything else, check the official source for your city and state. A calculation also cannot decide a disputed fact, such as whether keys were returned on the 9th or the 10th, or whether a lease allows proration at all for a particular month. Those questions are settled by the lease wording, written communications and evidence, and the arithmetic should be redone once they are settled, not before.

Sources

• Formulas: actual-days = rent ÷ days in the month × days occupied; 30-day = rent ÷ 30 × days occupied; 365-day = rent × 12 ÷ 365 × days occupied.
• State and city rules: Check official source. Only the verified rules in Rent Rules Explained are asserted on this site.

Frequently asked questions

Which proration method is most common?

The actual-days method is widely used because it matches the calendar, but leases vary. The 30-day method is also common for its simplicity. Check your lease — there is no single universal method.

Do I pay prorated rent for the move-in day?

Usually yes, if you take possession that day, but confirm how your agreement counts the first and last days.

What about February?

Use the actual number of days in that February — 28 in a normal year, 29 in a leap year — for the actual-days method. The 30-day method still divides by 30.

Should I round the daily rate or the final total?

Round only the final total to cents. Keep the daily rate at full precision through the multiplication, because rounding it first can shift the total by a few cents and make a correct bill look wrong, or a wrong bill look correct.

What if my rent is due on the 15th, not the 1st?

Prorate over the rental period your lease defines, not automatically over a calendar month. Confirm those period dates in writing before calculating.

Do I prorate utilities the same way as rent?

Not necessarily. Utilities may be billed by usage, by a fixed share, or by a separate agreement, and none of those follows automatically from the rent method. Keep rent and utilities as separate lines, and check the agreement for each one.

What if I move in and out in the same month?

Pay only for the days occupied, under the lease method. Count the occupied days inclusively, check whether the move-in and move-out days both count, and keep the key handover dates, because a same-month stay turns entirely on a small day count.

What if my lease does not mention proration at all?

Ask the landlord to confirm the method in writing before you pay, and keep the reply with the lease. Do not assume actual days, 30-day or 365-day applies merely because it is common elsewhere; a silent lease is a question to resolve, not a method to guess.

Last updated: 2026-10-25. Last verified for state rules: 2026-10-25.