Real estate math intimidates more candidates than any other single topic on the exam, but the underlying operations are more repetitive than they look. A relatively small set of formulas — commission splits, prorations, loan-to-value, and simple interest — covers most of what candidates run into. The exact mix and difficulty of math questions varies from state to state, so treat this as a toolkit for understanding the mechanics, not a guaranteed list of what will appear on your specific exam.
Commission math
Commission problems almost always start with the same structure: sale price × commission rate = total commission. From there, that total is typically split — first between the listing brokerage and the selling (buyer's) brokerage, and then again between each brokerage and its agent.
Worked example (using round, hypothetical numbers): a home sells for $300,000 with a 6% total commission. That's $300,000 × 0.06 = $18,000 in total commission. If the listing and selling brokerages split that 50/50, each brokerage receives $9,000. If an agent's individual split with their own broker is 70/30 in the agent's favor, the agent nets 70% of their brokerage's $9,000 share, or $6,300.
The trap most candidates fall into isn't the multiplication — it's losing track of which split applies at which step, or which number a question is asking for (total commission, one brokerage's share, or one agent's take-home). Read commission questions slowly and identify exactly which figure is being requested before doing any math.
Related: What to Expect on Your State’s Real Estate Salesperson Licensing Exam
Proration math
Prorations divide a recurring, periodic expense — most commonly property taxes, but sometimes HOA dues, rent, or insurance — between a buyer and seller based on how much of the billing period each of them actually owned the property. The general approach is: figure out the total amount owed for the full period, convert that into a daily rate, then multiply by the number of days each party is responsible for.
Worked example: an annual property tax bill of $3,650, prorated using a 365-day year, comes out to $10 per day ($3,650 ÷ 365). A seller who owned the property for 200 days of that tax year before closing would be responsible for 200 × $10 = $2,000, with the buyer responsible for the remaining $1,650.
Two things vary enough by state and by exam that you should confirm rather than assume: whether the calculation uses a 365-day or a 360-day year, and whether the day of closing itself is charged to the buyer or the seller. Different exams and different closing customs handle both differently, so don't lock in a single convention as universally correct.
Loan-to-value (LTV) ratio
LTV compares the size of a loan to the value of the property securing it: LTV = loan amount ÷ property value (typically the lesser of appraised value or sale price). A buyer borrowing $180,000 on a property valued at $225,000 has an LTV of $180,000 ÷ $225,000 = 80%.
LTV questions on the exam usually test the formula itself, or ask you to work backward to find the down payment or loan amount given a target LTV. LTV is also conceptually tied to mortgage insurance requirements on many conventional loans, since lenders commonly require it above certain LTV thresholds — but the exact threshold and requirements depend on the loan type and lender, so don't treat any single number as a fixed rule across all loan products.
Simple interest
Simple interest problems use the formula: Interest = Principal × Rate × Time, where the rate is typically an annual rate and time is expressed in years (or a fraction of a year, like 6 months = 0.5). This formula shows up in note and financing problems, including seller-financing scenarios and questions about how much interest accrues over a given period on a loan balance.
Bottom line
These four formulas — commission math, proration, LTV, and simple interest — cover the large majority of the calculation-based questions candidates encounter. Practice with realistic numbers rather than memorizing specific answers, keep a clear formula sheet rather than relying on memory under time pressure, and confirm ahead of time what type of calculator (if any) your specific exam allows. Try our real estate exam practice questions.