Move in on the 10th and you should not pay for the 1st through the 9th. This Prorated Rent Calculator converts your monthly rent into a daily rate and charges only for the days you actually occupy — the standard partial-month computation used by landlords and property managers, shown step by step so you can verify any invoice.
Worked Example: $1,500 Rent, Moving In on the 10th
April has 30 days, so the daily rate is 1500 / 30 = $50 per day. Moving in on the 10th means occupying the 10th through the 30th inclusive: 30 − 10 + 1 = 21 days. The prorated first payment is 21 × 50 = $1,050 — exactly 70% of a full month, which makes sense, since you are renting 70% of the month. The same machinery handles move-outs in reverse (a tenant leaving on the 12th of a 31-day month owes 12 days), mid-month rent increases, and roommate splits where one person arrives later than another. The inclusive-counting is the detail to watch: the move-in day itself is a day of occupancy in the standard convention, which is why the formula adds the 1 back.
The Three Conventions Landlords Actually Use
This page uses the most common method — actual days in the month — but two rivals exist, and knowing them explains a landlord’s “different” number. Banker’s month (30-day): every month counts as 30 days, so the daily rate is rent/30 year-round; a Feb 10 move-in then charges 21 days at the same rate, but a move-in on the 31st of a long month is treated as the 30th. Annual daily rate: the daily rate is (rent × 12)/365, spreading rent evenly across the year — this makes February’s daily rate lower than January’s and is common in commercial leases. For our example the annual method gives (1500 × 12)/365 = $49.32/day × 21 = $1,035.62 — close to, but not equal to, the $1,050 above. Neither is “wrong”; leases should name the method, and when one does not, the actual-days method is the usual default assumption in residential practice.
First Month, Deposits and the Real Move-In Bill
Proration is only one line of the move-in invoice. A typical first payment combines the prorated first month, the first full month in advance when the move-in date falls after mid-month (many landlords collect the prorated stub plus the coming full month together), a security deposit (often one month’s rent, capped by state law in many jurisdictions), and small fees. For the example tenant that might read: $1,050 stub + $1,500 deposit = $2,550 due at signing, with the next full $1,500 due on the 1st. Verifying the stub line with this calculator takes ten seconds and is worth doing — proration errors are common, almost always innocent, and much easier to question before the lease is signed than after. Keep the calculation: a screenshot of the daily rate and day count settles most disputes by itself.
Partial Months at the End of a Lease
The mirror problem appears at move-out: notice given mid-month, a lease ending on the 18th, or a holdover of a few days. The computation is identical — daily rate times days occupied — with two practical wrinkles. First, many leases convert to month-to-month at the end, in which case a partial final month may not be offered at all; the lease text governs, not convention. Second, holdover days are frequently charged at a premium (150% of the daily rate is a common clause), so a 5-day overstay on this example’s lease would be 5 × $75 = $375, not $250. Read the clause before assuming the friendly arithmetic applies — this calculator prices occupancy at the standard rate, which is the baseline every premium is measured from.
Common Mistakes
Counting the move-in day as free (it is a day of occupancy — the +1 in the formula). Using 30 days for every month when the lease specifies actual days. Letting the landlord prorate by weeks (4 weeks ≠ a month; a weekly conversion systematically overcharges in long months). And forgetting February: a 28-day month raises the daily rate on the actual-days method — $1,500 rent is $53.57 a day in February against $48.39 in a 31-day month — which cuts both ways depending on whether you are the one moving in or out.
Related Tools
Continue with the 50/30/20 Rule Calculator, the Percent Off Calculator, the Pay Raise Calculator, or browse the full Finance Calculators hub.
Frequently Asked Questions
How is prorated rent calculated?
Divide the monthly rent by the days in the month to get the daily rate, then multiply by the days you occupy. Moving in on the 10th of a 30-day month at $1,500 rent: $50/day × 21 days = $1,050.
Do I pay for the move-in day itself?
Yes, under the standard convention — you occupy the unit that day. The day count runs from the move-in day through the last day of the month, inclusive, which is why the formula adds 1.
Why did my landlord get a different number?
Probably a different convention: a flat 30-day month, or an annual daily rate (rent × 12 / 365). Both are legitimate if the lease names them; ask which method was used and recompute.
How does proration work for a move-out?
Identically: daily rate times days occupied in the final month. Leaving on the 12th of a 31-day month at $1,500 means 12 days at $48.39 = $580.65, unless your lease converts to month-to-month or charges holdover premiums.
Is February prorated differently?
On the actual-days method, yes: the daily rate rises because the same rent covers fewer days — $53.57/day for $1,500 in a 28-day February. The banker’s-month method avoids this by always dividing by 30.
Can a landlord refuse to prorate?
For the first month, proration is near-universal practice, but the lease text governs. For final partial months, many leases require the full month or convert to month-to-month terms — check the document before assuming.