NY Real Estate Math Practice: The 10 Formulas You Must Know

The 10 NY Real Estate Math Formulas You Must Know for the Exam

Real estate math sinks more candidates on the NY salesperson exam than any other topic. Most candidates can memorize agency rules, fair housing classes, and contract terms. Math is different — you have to apply the formula to a scenario under a 90-minute timer with PSI’s on-screen calculator. The good news: every math question on the exam is built from a small set of repeatable formulas. Master these ten and you take a major source of points off the table.

This guide walks through each formula, shows a worked example, and gives a quick check you can do in under 60 seconds. By the end, you will have a clean reference sheet you can drill before your test.

1. Commission Calculations

Commission is the most common math question on the NY salesperson exam. Expect at least two to four problems on this alone.

Formula: Commission = Sale Price × Commission Rate

Worked example: A home sells for $385,000 with a 6% commission rate. The total commission is $385,000 × 0.06 = $23,100. If the listing brokerage and selling brokerage split it 50/50, each brokerage receives $11,550. If the salesperson and broker split that 60/40 in favor of the salesperson, the salesperson earns $6,930.

Watch for: Multi-step splits. The exam often layers in a brokerage split, then an in-house split between agent and broker. Read every sentence before you start calculating.

2. Sale Price From Commission

The reverse of formula one. You are given the commission earned and the rate, and asked to find the sale price.

Formula: Sale Price = Commission ÷ Commission Rate

Worked example: An agent earns $9,600 commission at a 4% rate. The sale price is $9,600 ÷ 0.04 = $240,000.

Watch for: When the question gives you the agent’s portion (after a brokerage split), back into the gross commission first, then divide by the rate.

3. Percentage Change (Appreciation and Depreciation)

Used for property value gains, value losses, and price reductions.

Formula: Percentage Change = (New Value − Original Value) ÷ Original Value × 100

Worked example: A home was purchased for $250,000 and is now worth $310,000. Appreciation = ($310,000 − $250,000) ÷ $250,000 × 100 = 24%.

Watch for: The denominator is always the original value, never the new value. Mixing those is the most common error on this question type.

4. Loan-to-Value Ratio (LTV)

LTV is what lenders use to size a mortgage against a property’s value. The exam tests this in financing scenarios.

Formula: LTV = Loan Amount ÷ Property Value × 100

Worked example: A buyer takes a $240,000 mortgage on a property valued at $300,000. LTV = $240,000 ÷ $300,000 × 100 = 80%. That is the maximum LTV for a conventional loan without private mortgage insurance.

Watch for: Use the lower of purchase price or appraised value as the denominator. The exam will sometimes give you both.

5. Down Payment

Often paired with LTV in the same problem.

Formula: Down Payment = Property Value × (1 − LTV)

Worked example: Property valued at $400,000 with an 85% LTV mortgage. Down Payment = $400,000 × 0.15 = $60,000.

Watch for: Down payment percent and LTV always add to 100%. If LTV is 90%, down payment is 10%.

6. Simple Interest on a Loan

The exam uses simple interest to test understanding of how interest accrues over a fixed period.

Formula: Interest = Principal × Rate × Time

Worked example: A $20,000 loan at 6% annual interest for 9 months. Time must be in years: 9 ÷ 12 = 0.75. Interest = $20,000 × 0.06 × 0.75 = $900.

Watch for: Always convert months or days to a fraction of a year before multiplying.

7. Property Tax Proration

At closing, property taxes already paid by the seller are refunded for the days the buyer will own the property. The exam loves this calculation.

Formula: Daily Tax = Annual Property Tax ÷ 365 (or ÷ 360 if the question specifies a banker’s year). Then multiply daily tax by the number of days each party owns the property.

Worked example: Annual taxes are $7,300. Closing happens on day 200 of the year. Daily tax = $7,300 ÷ 365 = $20. Seller owes the buyer for the remaining 165 days: $20 × 165 = $3,300 credit to buyer at closing.

Watch for: Read whether the question uses a 365-day or 360-day year. Both appear on the exam.

8. Gross Rent Multiplier (GRM)

GRM is a quick valuation tool used for income-producing properties.

Formula: GRM = Property Value ÷ Annual Gross Rental Income

Worked example: A property is valued at $480,000 and produces $60,000 in annual gross rent. GRM = $480,000 ÷ $60,000 = 8. That means the property sells for eight times annual rent.

Watch for: GRM uses gross rent (before expenses), not net. The variation Gross Income Multiplier (GIM) uses monthly rent — read carefully which one the question asks for.

9. Area and Square Footage

Tests basic geometry applied to lots and buildings. Two shapes appear most often: rectangles and triangles.

Formula: Rectangle Area = Length × Width. Triangle Area = (Base × Height) ÷ 2. Acres conversion: 1 acre = 43,560 square feet.

Worked example: A rectangular lot is 200 feet wide and 300 feet deep. Area = 200 × 300 = 60,000 square feet. In acres: 60,000 ÷ 43,560 = 1.38 acres.

Watch for: Memorize 43,560 square feet per acre. The exam expects you to convert without prompting.

10. Capitalization Rate (Cap Rate)

The income approach to valuation, tested in the appraisal section.

Formula: Cap Rate = Net Operating Income ÷ Property Value × 100

Worked example: A commercial property generates $48,000 net operating income (NOI) on a $600,000 value. Cap Rate = $48,000 ÷ $600,000 × 100 = 8%.

Worked rearrangement: If you know the NOI and the cap rate, solve for value: Value = NOI ÷ Cap Rate. $48,000 ÷ 0.08 = $600,000.

Watch for: Net Operating Income is gross income minus operating expenses, not minus mortgage payments. Mortgage debt service is not part of NOI.

How to Practice These Formulas

Reading the formulas is not enough. The exam tests speed under pressure, which means you need to drill until each problem type takes you under 90 seconds.

A practical study sequence:

• Day 1–2: Write each formula on an index card with one worked example. Quiz yourself until you can recall every formula without looking.
• Day 3–5: Solve five timed problems per formula type. Use a stopwatch and aim for under 90 seconds per problem.
• Day 6–7: Take a full mixed practice quiz with all ten formulas in random order. This mirrors the exam where math problems are scattered, not grouped.

Our NY Real Estate Practice Tests include a full pool of math questions across all ten formulas, with instant answer review so you can see exactly where you went wrong. The free 10-question diagnostic quiz is a fast way to baseline your math skill before you commit to a study plan.

Common Mistakes to Avoid

Three errors account for most missed math questions:

• Skipping unit conversions. Months to years, square feet to acres, percent to decimal — every conversion is a chance to lose points if you skip it.
• Using the wrong base for percentages. Original value, not new value, is almost always the denominator. Re-read the question and identify the base before you calculate.
• Confusing gross with net. GRM uses gross rent. Cap rate uses net operating income. Mixing them produces wrong answers that look reasonable.

Final Reference Sheet

Print this list and review it the morning of your exam:

• Commission = Sale Price × Rate
• Sale Price = Commission ÷ Rate
• % Change = (New − Original) ÷ Original × 100
• LTV = Loan ÷ Value × 100
• Down Payment = Value × (1 − LTV)
• Simple Interest = Principal × Rate × Time
• Daily Tax = Annual Tax ÷ 365, then multiply by days
• GRM = Value ÷ Annual Gross Rent
• Rectangle Area = L × W. 1 acre = 43,560 sq ft
• Cap Rate = NOI ÷ Value × 100

Real estate math feels intimidating until you realize how few patterns it actually contains. Ten formulas, drilled to fluency, will carry you through every math question on the NY salesperson exam. Combine that fluency with timed practice, and the math section becomes one of your highest-scoring topics rather than the place you lose the exam.

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