Prorated Rent Calculator — Actual Days vs Banker's 30-Day

Calculate prorated rent for a partial month using the actual days-in-month and banker's 30-day methods side by side, plus which states require which.

July 13, 2026

Monthly Rent ($)

Move Type

Move-In Date

Proration Method

Actual Days method: Daily Rate = Monthly Rent ÷ actual days in that month, then × days occupied. Banker's 30-Day method: Daily Rate = Monthly Rent ÷ 30 (always), then × days occupied. There's no single universal standard — which method applies depends on your lease terms and jurisdiction, so both are shown for comparison. This calculator doesn't know your specific lease or state law; confirm the required method before relying on the number.

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Reference Values

Last verified: Jul 11, 2026

Category	Range	What It Means	Status
Actual Days-in-Month Method	Monthly Rent ÷ actual days in that month	Daily rate is Monthly Rent ÷ 28, 29, 30, or 31 depending on the specific month, then multiplied by days occupied. Produces a different daily rate every month.	Good
Banker's 30-Day Method	Monthly Rent ÷ 30 (always)	Daily rate is fixed at Monthly Rent ÷ 30 regardless of how many days the month actually has, then multiplied by days occupied. Simpler, but not equal-cost across months.	Good
California requirement ★	Banker's 30-day method	California landlord-tenant guidance and standard lease practice treat the rental month as a flat 30 days for proration purposes, following the state's statutory monthly-to-daily rent conversion convention.	★ Best
Texas requirement ★	Actual days-in-month method	Texas practice and standard lease templates prorate using the real number of days in the specific calendar month rather than a flat 30, so the daily rate changes month to month.	★ Best
31-day months (Jan, Mar, May, Jul, Aug, Oct, Dec)	Banker's method costs tenant more	Because the banker's method divides by 30 instead of 31, its daily rate is higher in every 31-day month, so it always produces a larger prorated charge than the actual-days method in these months.	Okay
February (28 or 29 days)	Banker's method costs tenant less	February is the only month where dividing by 30 produces a lower daily rate than the actual number of days, so the banker's method is the one month it favors the tenant instead of the landlord.	Okay
30-day months (Apr, Jun, Sep, Nov)	Both methods match exactly	When the actual month length is exactly 30 days, the actual-days and banker's 30-day methods produce identical daily rates and identical prorated rent.	Good

Source: Landlord Studio prorated rent calculator methodology; RentLateFee.com, "Prorated Rent: 30 or 31 Days?"; Rentec Direct, "4 Ways to Calculate Prorated Rent." Proration method requirements vary by state and by individual lease terms — always confirm against your specific lease and local landlord-tenant law.

Worked Examples

Move-In Mid-Month in a 31-Day Month — Both Methods Compared

Monthly Rent: $1,500
Move-In Date: July 15
Days Occupied: 17 of 31 days

$822.58 (actual days) vs $850.00 (banker's 30-day)

Actual days: $1,500 ÷ 31 = $48.39/day × 17 days = $822.58. Banker's 30-day: $1,500 ÷ 30 = $50.00/day × 17 days = $850.00. The banker's method charges $27.42 more because July has 31 days but the method still divides by 30.

February Move-Out — The One Month the Banker's Method Favors the Tenant

Monthly Rent: $1,200
Move-Out Date: February 10, 2026
Days Occupied: 10 of 28 days

$400.00 (banker's) vs $428.57 (actual days)

Actual days: $1,200 ÷ 28 = $42.86/day × 10 days = $428.57. Banker's 30-day: $1,200 ÷ 30 = $40.00/day × 10 days = $400.00. Because February 2026 has only 28 days, dividing by 30 produces a lower daily rate — the only calendar month where the banker's method costs the tenant less instead of more.

30-Day Month — Both Methods Produce the Same Result

Monthly Rent: $2,000
Move-In Date: April 21
Days Occupied: 10 of 30 days

$666.67 (identical under both methods)

Actual days: $2,000 ÷ 30 = $66.67/day × 10 days = $666.67. Banker's 30-day: $2,000 ÷ 30 = $66.67/day × 10 days = $666.67. April has exactly 30 days, so the two formulas collapse into the same daily rate — this only happens in April, June, September, and November.

Texas Move-Out — Actual-Days Method Required by State Practice

Monthly Rent: $1,800
Move-Out Date: January 20
Days Occupied: 20 of 31 days

$1,161.29 (actual-days, Texas-compliant)

Actual days: $1,800 ÷ 31 = $58.06/day × 20 days = $1,161.29. For comparison, the banker's 30-day method would give $1,800 ÷ 30 = $60.00/day × 20 days = $1,200.00 — $38.71 more. Texas leases typically use the actual-days method, so the $1,161.29 figure is the one a Texas tenant should expect.

California Move-In — Banker's 30-Day Method Required by State Practice

Monthly Rent: $1,650
Move-In Date: December 20
Days Occupied: 12 of 31 days

$660.00 (banker's, California-compliant)

Banker's 30-day: $1,650 ÷ 30 = $55.00/day × 12 days = $660.00. For comparison, the actual-days method would give $1,650 ÷ 31 = $53.23/day × 12 days = $638.71 — $21.29 less. California's standard 30-day monthly-to-daily rent conversion means the $660.00 figure is the one a California tenant should expect.

How to Use This Calculator

1

Enter your monthly rent

The full, unprorated monthly rent amount stated in your lease.
2

Choose Move-In or Move-Out

Determines whether days occupied are counted from your move date through the end of the month, or from the start of the month through your move date.
3

Pick your move date

The calendar date you moved in or will move out — the calculator automatically finds how many days are in that month.
4

Compare both proration methods

The result highlights your selected method but always shows the actual-days and banker's 30-day amounts side by side, with the dollar difference between them.

What Each Value Means

Actual Days-in-Month Method ($/day): A proration formula that divides monthly rent by the real number of days in the specific calendar month (28, 29, 30, or 31) to get a daily rate, then multiplies by days occupied.
Banker's 30-Day Method ($/day): A proration formula that divides monthly rent by a fixed 30 days regardless of the month's actual length, then multiplies by days occupied.
Days Occupied (days): The number of calendar days counted for proration — from the move-in date through the end of the month, or from the start of the month through the move-out date, both inclusive.

Frequently Asked Questions

Why does this calculator show two different answers for the same dates?

Because there's no single national standard for calculating prorated rent — landlords and leases use one of two common formulas. The actual-days method divides monthly rent by the real number of days in that specific calendar month (28 to 31), while the banker's 30-day method always divides by a flat 30, regardless of the month's real length. The two only agree in April, June, September, and November, since those are the only calendar months that actually have 30 days. This calculator shows both so you can see exactly how much they differ before assuming which one applies to you.

Which states require which proration method?

California landlord-tenant practice generally uses the banker's 30-day method, treating every month as a flat 30 days when converting monthly rent to a daily rate. Texas practice generally uses the actual-days method, dividing by the real number of days in the specific month. These are the two most commonly cited state examples, but proration rules aren't uniform nationwide — many states leave the method up to the lease itself rather than mandating one by law. Always check your own state's landlord-tenant statute and your signed lease, since either can override a general assumption.

Does the banker's 30-day method always cost more?

No — it costs more in every month with 31 days (January, March, May, July, August, October, December) because dividing by 30 produces a higher daily rate than dividing by 31. But in February, which has only 28 days (29 in a leap year), dividing by 30 produces a lower daily rate than dividing by the real day count — making February the one month where the banker's method actually favors the tenant instead of the landlord.

Is the move-in day or move-out day counted as a full day of rent?

This calculator counts the move-in date itself as the first day of occupancy, and the move-out date itself as the last day of occupancy — both inclusive. So moving in on the 15th of a 31-day month means 17 days occupied (the 15th through the 31st), and moving out on the 20th means 20 days occupied (the 1st through the 20th). Some leases instead prorate to the day before or after a move date, so confirm your specific lease's counting convention if the exact day matters for your situation.

Can my landlord choose whichever method gives them more money?

In states without a specific statutory requirement, a landlord can generally set the proration method in the lease itself, and it doesn't have to be the one that's most favorable to the tenant. What they typically can't do is silently switch methods between your move-in and move-out to always land on the higher number in both directions — most leases and state guidance expect one consistent method to be applied to the tenancy. If your lease doesn't specify a method, ask your landlord or property manager which one they use before you move, and get it in writing.