If there is one mathematical concept that consistently intimidates real estate students, it is proration. However, mastering proration calculations step by step is absolutely essential for passing the California Department of Real Estate (DRE) licensing exam. Prorations are the mathematical division of expenses between a buyer and a seller during the close of escrow. Because property ownership transitions on a specific day, ongoing expenses like property taxes, homeowner association (HOA) fees, and rental income must be fairly divided.

In this guide, we will break down the exact formulas, rules, and timelines you need to know to ace the math portion of your exam. For a broader overview of everything you need to study, be sure to bookmark our Complete California Exam Guide.

Understanding the California Standard: The Banker's Year

Before you punch a single number into your calculator, you must understand the calendar used by the California DRE for exam purposes. Unless a test question specifically tells you to use a 365-day calendar year, you must use the Banker's Year (also known as a statutory year).

  • 1 Year = 360 days
  • 1 Month = 30 days (regardless of whether it's February or October)

This standardized calendar simplifies calculations. Furthermore, standard California escrow practice dictates that the buyer is responsible for the day of closing. This means the seller pays for expenses up to the day before closing, and the buyer assumes responsibility starting on the exact closing date.

Step-by-Step Proration Calculation Method

Whether you are acting as a buyer's agent or a seller's agent—which carries distinct fiduciary duties outlined in our Buyer vs Seller Representation guide—you must be able to explain these closing costs to your clients. Follow these five steps to solve any DRE proration question.

Step 1: Identify the Total Amount and Period

Read the question to find the total bill being prorated and the timeframe it covers. Is it an annual property tax bill? A monthly HOA fee? A monthly rent payment?

Step 2: Calculate the Per Diem (Daily Rate)

Divide the total amount by the number of days in the billing period to find the daily cost. For an annual expense, divide by 360. For a monthly expense, divide by 30.

Formula: Total Expense ÷ Total Days in Period = Per Diem Rate

Step 3: Determine the Number of Days

Count the exact number of days the seller owned the property (or the buyer will own the property) during the billing period. Remember to use the 30-day month rule.

Step 4: Calculate the Prorated Amount

Multiply the Per Diem rate by the number of days you calculated in Step 3.

Formula: Per Diem Rate × Number of Days = Prorated Amount

Step 5: Assign Debits and Credits

Determine who owes money (Debit) and who receives money (Credit). A debit is money taken away; a credit is money given.

  • If the seller prepaid an annual expense, the buyer owes the seller for the unused portion (Credit Seller, Debit Buyer).
  • If an expense is paid in arrears (at the end of the year), the seller owes the buyer for the days they lived there (Debit Seller, Credit Buyer).

Typical Prorated Escrow Amounts in CA Transactions ($)

California Property Tax Proration Scenario

Property taxes are the most common proration questions on the state exam. You must remember that the California property tax year runs from July 1 through June 30. Unpaid property taxes take precedence over almost all other claims, which you can read more about in our guide on Liens and Their Priority.

Example Scenario:
A property closes escrow on October 15th. The annual property taxes are $3,600. The seller has already paid the first installment of taxes (covering July 1 through December 31). How will this be prorated at closing?

Step 1: Total Amount & Period
The seller paid for 6 months (July 1 to Dec 31). Half of $3,600 is $1,800. The seller paid $1,800.

Step 2: Per Diem Rate
$3,600 annual tax ÷ 360 days = $10 per day.

Step 3: Number of Days
The seller owned the home from July 1 up to October 14 (the buyer owns the day of closing, Oct 15).
July = 30 days
August = 30 days
September = 30 days
October = 14 days
Total Seller Days = 104 days.

Step 4: Calculate Prorated Amount
The seller was responsible for 104 days. 104 days × $10/day = $1,040.
The seller actually paid $1,800 for the half-year. They overpaid by the difference: $1,800 - $1,040 = $760.

Step 5: Assign Debits and Credits
Because the seller prepaid past their ownership date, the buyer must reimburse them.
Answer: Credit Seller $760, Debit Buyer $760.

Rent Proration Scenario

Unlike determining a property's list price using a Comparative Market Analysis, prorating rent requires strict adherence to the rental contract dates. Rent is typically paid in advance on the 1st of the month.

Example Scenario:
A duplex is sold, and escrow closes on September 21st. The tenant pays $2,400 per month in rent, which was collected by the seller on September 1st. What is the proration?

Step 1: Total Amount & Period
Total rent is $2,400 for the month of September.

Step 2: Per Diem Rate
$2,400 ÷ 30 days (Banker's month) = $80 per day.

Step 3: Number of Days
The buyer owns the property starting on the closing date (September 21). Therefore, the buyer is entitled to rent for Sept 21 through Sept 30.
30 days total - 20 days seller owned = 10 days buyer owns.

Step 4: Calculate Prorated Amount
10 days × $80/day = $800.

Step 5: Assign Debits and Credits
The seller collected the whole month's rent but only gets to keep 20 days' worth. They must give the remaining 10 days' worth to the buyer.
Answer: Debit Seller $800, Credit Buyer $800.

Frequently Asked Questions (FAQs)

Do I use a 365-day year or a 360-day year on the California real estate exam?

Always use the 360-day Banker's Year (and 30-day months) for proration math on the California DRE exam unless the specific question explicitly tells you to use a 365-day calendar year.

Who owns the property on the day of closing in California?

For exam purposes and standard California escrow practices, the buyer is considered the owner of the property on the day of closing. Therefore, the buyer is responsible for taxes, insurance, and interest starting on that exact date, and is entitled to any rental income from that day forward.

What are the critical dates for California property tax prorations?

The California property tax year runs from July 1 through June 30. Taxes are paid in two installments. The first installment is due November 1 (late December 10) and covers July 1 - December 31. The second installment is due February 1 (late April 10) and covers January 1 - June 30. Memorizing these dates is vital for accurate tax prorations.

What is the difference between a debit and a credit in escrow?

A debit is an expense or a charge—it is money you owe and must pay out of your pocket or out of your proceeds. A credit is money you receive or money that reduces your overall closing costs.

How do leap years affect proration calculations on the exam?

Because the DRE exam relies on the 360-day Banker's Year, leap years do not affect your calculations at all. Every month, including February, is treated as having exactly 30 days.