Prorated Rent Calculator
On a $1,500/month rent with a move-in on February 15, 2026 (a 28-day, non-leap month), the standard actual-days method prorates the first month at $750.00 ($53.57/day × 14 days). The same move date under the 30-day banker's method comes to $700.00, and under the 365-day annual method to $690.41 — a $59.59 swing depending on which method your lease uses. Enter your own rent and dates below to see all three at once.
$677.42 under the actual-days method
Days occupied: 14 of 31 · Daily rate: $48.39
Depending on which proration method your lease specifies, the same move date can prorate anywhere from $677.42 to $700.00 — a spread of $22.58.
All 3 proration methods, side by side
| Method | Daily rate | Divisor | Days occupied | Prorated amount |
|---|---|---|---|---|
| Actual days in month | $48.39 | ÷31 | 14 | $677.42 |
| 30-day banker's month | $50.00 | ÷30 | 14 | $700.00 |
| 365-day annual | $49.32 | ÷365 | 14 | $690.41 |
Cheapest for the tenant: Actual days in month · Most expensive: 30-day banker's month
"Actual days in month" divides rent by the real day-count of the specific month (28-31, correctly handling leap-year Februaries). "30-day banker's month" always divides by 30. "365-day annual" divides the annualized rent (rent × 12) by 365. Which method applies is set by your lease — not by federal law.How we calculate →
Three ways to prorate rent — and why they don't agree
Every landlord tool prorates rent the same basic way: find a daily rent, then multiply by the days the tenant actually occupies the unit. Where they differ is the divisor used to get that daily rate — and that divisor changes the answer by real money.
The actual-days method divides the monthly rent by the true number of days in that specific calendar month — 28 in February 2026, 29 in a leap February, 30 in April/June/September/November, 31 in the rest. The 30-day banker's method always divides by 30, no matter how long the month actually is. The 365-day annual method treats the rent as an annual figure (monthly rent × 12) divided by 365, spreading the cost evenly across every day of the year regardless of month length.
On the $1,500/month, February 15 move-in example above, that's $53.57/day (actual-days, ÷28) vs $50.00/day (30-day, ÷30) vs $49.32/day (365-annual) — a difference of $59.59 on the final prorated charge for the exact same move date.
The leap-year trap: same date, different divisor
February is the month where this matters most, because its length itself changes. A $1,500/month, February 15 move-in prorates to $750.00 under the actual-days method in 2026 (28 days in the month) — but to $775.86 for the identical move date in 2028, a leap year (29 days). The 30-day and 365-day methods don't move at all between the two years, because neither one looks at how many days February actually has — which is exactly why some leases specify a fixed divisor: it makes the number predictable year to year, at the cost of not reflecting the real calendar.
Move-out proration works the same way, in reverse
Moving out mid-month uses the identical formula, just counting days 1 through the move-out date instead of the move-out date through month-end. For a $1,800/month rent with a move-out on August 22 (a 31-day month), the actual-days method owes $1,277.42 for the 22 days occupied ($58.06/day), while the 30-day method owes $1,320.00 — $42.58 more, because ÷30 produces a higher daily rate than ÷31 for a 31-day month.
Which method should you use? Check the lease first
There's no single US federal law mandating one proration method over another for standard residential rent — none of the major landlord platforms we compared (TurboTenant, Zillow Rental Manager, Baselane) cite a specific method as legally required either. The method that applies is whichever your lease agreement specifies. If the lease is silent, actual-days is the most common default among the tools landlords use, and it's the only method that's mathematically neutral to which month the move happens in.
Some states and cities do regulate whether prorating is required at all (as opposed to which formula to use) and set rules around move-in/move-out timing and security deposits — check your state and local landlord-tenant law, since this varies by jurisdiction and this calculator doesn't model those rules.
Frequently asked questions
What is prorated rent?
Prorated rent is the amount a landlord charges (or a tenant pays) for occupying a rental unit for only part of a billing month — typically because the lease starts or ends on a day other than the 1st or last day of the month. Instead of charging a full month, the rent is scaled down to match the days actually occupied.
How do you calculate prorated rent?
Divide the monthly rent by a daily divisor, then multiply by the days occupied. The divisor is the point of disagreement between methods: the actual-days method uses the real number of days in that month (28-31), the 30-day method always uses 30, and the 365-day annual method uses (rent × 12) ÷ 365. For a $1,500/month rent moving in Feb 15, 2026, that's $750.00, $700.00, and $690.41 respectively.
Which proration method is most common?
The actual-days method (dividing by the real number of days in the specific month) is the default — and in our competitor audit, the only method — used by TurboTenant's and Zillow's calculators. Baselane offers a 30-day alternative as a toggle. The 365-day annual method is less common for residential leases and shows up more often in commercial lease CAM (common-area-maintenance) reconciliations.
Do landlords have to prorate rent?
Not automatically under federal law. Whether rent is prorated — and by which method — is governed by the lease agreement first, and by state/local landlord-tenant law second. It's very common practice because it's seen as fair to both sides, but check your lease and jurisdiction for any specific requirement.
How do I prorate rent for a move-out mid-month?
Use the same formula as for a move-in, but count the days from the 1st of the month through the move-out date (inclusive) instead of from the move-in date through month-end. The daily rate calculation (actual-days, 30-day, or 365-annual) is identical either direction.
Does a leap year change prorated rent?
Only under the actual-days method, and only for February. A February move affects a 28-day month in a normal year but a 29-day month in a leap year (2028, 2032...), which changes the daily rate slightly. The 30-day and 365-day methods are unaffected by leap years since neither looks at the real length of the specific month.
What's the difference between the 30-day and 365-day proration methods?
The 30-day (banker's month) method divides monthly rent by a flat 30, regardless of the actual month length. The 365-day annual method instead annualizes the rent (× 12) and divides by 365, spreading the cost evenly across a full calendar year. Both ignore the real day-count of the specific month the move falls in, which is what separates them from the actual-days method.
Should the prorated rent amount be written into the lease?
It's good practice to state the prorated amount (and which proration method was used) in the lease or a signed addendum before move-in, so there's no dispute later about which formula applied. Once signed, the lease terms govern.
Related calculators
- Paycheck Calculator — figure out the take-home pay you'll have available for a prorated first or last month's rent.
- Percentage Calculator — for any other percentage-of-a-total split, like a security deposit percentage or a roommate rent share.
Researched & verified by the Calcuris Data & Research Team. How we build and check our tools →