EstatePass
Real Estate Math

Loan Qualification Math

Loan qualification math involves calculating the debt-to-income ratios that lenders use to determine whether a borrower qualifies for a mortgage. The two primary ratios are the front-end (housing expense) ratio and the back-end (total debt) ratio.

Understanding Loan Qualification Math

The front-end ratio compares monthly housing expense (PITI—principal, interest, taxes, insurance, plus HOA or PMI) to gross monthly income. The back-end ratio compares all monthly debt obligations (housing expense plus car payments, student loans, credit card minimums) to gross monthly income. Conventional loans typically require 28% front-end and 36% back-end maximum. FHA allows up to 31%/43%. VA primarily uses the back-end ratio at 41%.

Real-World Example

A borrower earns $6,000/month gross. PITI is $1,500 and other debts are $300/month. Front-end ratio = $1,500 / $6,000 = 25%. Back-end ratio = ($1,500 + $300) / $6,000 = 30%. Under conventional guidelines (28%/36%), this borrower qualifies.

Visual Study Guide
Download and share these infographics to reinforce your understanding of Loan Qualification Math.
Exam Tips

Memorize the conventional thresholds: 28% front-end and 36% back-end. Know what is included in each ratio—PITI for the front-end, and PITI plus all recurring debts for the back-end. Always use gross (pre-tax) income, never net income.

Related Terms

Proration CalculationsCommission SplitsNet Operating Income

Related Concepts

Converting a percentage to a decimal involves dividing the percentage value by 100.

IRV stands for Income, Rate, and Value. It represents the relationship between Net Operating Income (I), Capitalization Rate (R), and Property Value (V).

Net Operating Income (NOI) is the revenue a property generates after deducting all operating expenses.

The gross rent multiplier (GRM) is a quick method for estimating the value of income-producing property by multiplying the property's gross rent by a factor derived from comparable sales. GRM = Sale Price / Gross Rent.

The capitalization rate (cap rate) is the ratio of a property's net operating income to its sale price, expressed as a percentage. It is used to estimate value and compare profitability of investment properties. Cap Rate = NOI / Value.

Frequently Asked Questions

Study This in Your State

Loan Qualification Math may have state-specific rules. Choose your state to study Real Estate Math with localized content:

Master This Concept

Practice with real exam questions and track your progress.

Get Started Free