Prorated Rent Calculator
Fair rent owed for a partial month of occupancy
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Prorated Rent Calculator turns the numbers behind fair rent owed for a partial month of occupancy into a result, step by step. Drop Monthly Rent ($), Occupied Days and Days in Month into Prorated Rent — the figure refreshes as you type. Nothing in Prorated Rent is a black box. Prorated Rent suits budgeting and planning checks. Prorated Rent is privacy-first: Finance inputs stay offline. Prorated Rent sits in the Finance section next to related tools and prorated rent calculator partial month move in move out daily rent. Prorated Rent shows formula, assumptions and result together. Try Prorated Rent now and keep it handy.
What half a month costs
Prorated rent = (monthly rent ÷ days in month) × days occupied. At the defaults — $1,200, 15 days of a 30-day month — the daily rate is $40 and the prorated rent is $600.
Fifteen days is exactly half of thirty, which is why the answer lands on half the rent. In a 31-day month the same 15 days cost $580.65, not $600.
The prorated rent formula
Prorated rent charges only the days you actually occupy the unit:
Prorated rent = Monthly rent ÷ Days in the month × Days occupied
For $1,800 rent in a 30-day month, moving in on the 16th (15 days): $1,800 ÷ 30 × 15 = $900.
| Days occupied | Prorated rent at $1,800/mo (30-day month) | Daily rate |
|---|---|---|
| 5 | $300.00 | $60.00 |
| 10 | $600.00 | $60.00 |
| 15 | $900.00 | $60.00 |
| 20 | $1,200.00 | $60.00 |
| 25 | $1,500.00 | $60.00 |
Some landlords divide by 30 or 31, others use the 365-day method — confirm which convention your lease uses. Related: roommate rent split and relocation cost.
The formula
Owed = (monthly rent ÷ days in month) × occupied days.
Daily rate = $1,200 ÷ 30 = $40.
Owed = $40 × 15 = $600.
Two conventions compete here, and the lease decides which applies: the actual day count of the month, or a standardised 30-day month. They only agree in a 30-day month, which is why August and February produce the awkward cases.
Worked examples
$1,200, 15 days, 30-day month → $600.
$1,200, 15 days, 31-day month → 38.71 × 15 = $580.65.
$1,200, 10 days, 28-day February → 42.86 × 10 = $428.60.
The 30-day convention is simpler and easier to explain, but it can cost either side money depending on the month — a tenant moving in for 15 days in February pays $600 under the standard method and $428.60 under the actual-day method.
What usually needs prorating
- Move-in mid-month. The most common case, and the one a landlord will calculate at the start of a tenancy.
- Move-out mid-month. The same arithmetic, usually deducted from the final payment.
- Rent changes. A mid-month increase is prorated so each rate covers only its own days.
- Utilities. Often prorated on the same day count when the bill covers a period you only partly occupied.
Mistakes to avoid
Using 30 days for every month is the classic error — in February it overcharges the tenant by roughly 7%. Counting the move-in day twice inflates the total by one day. And dividing by weeks rather than days (rent ÷ 4.33) gives a weekly average that does not prorate correctly at all. Agree the method in writing before the first payment, because a $170 difference on a February move is worth an argument.
Frequently Asked Questions
Why is 15 days of a $1,200 month $600?
Because the daily rate is $1,200 ÷ 30 = $40, and 15 × $40 = $600. Fifteen days is exactly half of a 30-day month.
Should I divide by 30 or by the actual days in the month?
Whichever the lease specifies. Actual days is fairer and standard in many jurisdictions; a flat 30-day month is simpler and common in leases that state it. The difference is up to about 7%.
Does the move-in day count?
Only once. Some landlords count both the move-in and move-out day, which adds a day of rent — check the lease, and count occupied days consistently.
How do I prorate a mid-month rent increase?
Split the month at the change date: old rent ÷ days × days at old rate, plus new rent ÷ days × days at new rate. The two parts added together are the amount owed.
Is prorated rent taxed the same way?
It is rent, so it is treated as rent — the same tax treatment as the full month, just smaller. It is not a discount or a fee.
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