House Affordability Calculator

Guide to Understanding Your Home Budget

Buying a home is a huge milestone. Before you start browsing listings or visiting open houses, you need a solid financial plan. We built this guide to help you make sense of the math lenders use so you can set realistic expectations.

Why this tool exists

We created this calculator to give you a clear and honest look at your home buying power. Lenders look at specific numbers to decide how much they are willing to lend you. This tool does the same math upfront so you can avoid surprises later and shop for homes in the right price range.

When should you use this calculator?

This tool is highly practical for anyone thinking about buying property. You will find it most useful when:

• You are planning to buy your first home and need a reliable starting budget.
• You want to see how a small change in interest rates affects your monthly mortgage payment.
• You are deciding whether to pay off a car loan or credit card before applying for a mortgage.
• You want to compare how different loan types, like FHA or VA loans, impact what you can borrow.

How the calculator works

You start by entering your gross annual income, your monthly debts, and the down payment you expect to make. The calculator then applies standard lending rules to find your maximum allowed monthly housing payment. From there, it works backward using the interest rate and loan term to estimate the highest home price you can comfortably afford.

The core numbers lenders look at

When you ask a bank for a mortgage, they do not just look at your savings account. They use specific ratios to determine if you can safely handle the loan.

Gross Monthly Income

This is the money you earn before taxes and deductions are taken out. It includes your base salary, bonuses, and other consistent income sources. Lenders use the gross amount to create a fair baseline because everyone has slightly different tax situations.

Debt-to-Income (DTI) Ratio

Your DTI is the percentage of your monthly income that goes toward paying off debts. This is the main number lenders use to measure your financial health. There are two types of DTI ratios:

• Front-End Ratio: This is the percentage of your income that goes specifically toward housing costs like principal, interest, property taxes, and insurance.
• Back-End Ratio: This includes your housing costs plus all your other monthly debts, like credit card minimums, car loans, and student loans.

The 28/36 rule explained

For a long time, the 28/36 rule has been a standard guideline for conventional home loans. Our calculator uses this rule by default. Here is what it means for your wallet:

• The 28% Limit: Your total household housing expenses should not exceed 28% of your gross monthly income.
• The 36% Limit: Your total debt, including the new mortgage, should not exceed 36% of your gross monthly income.

For example, if you earn $10,000 a month before taxes, a lender following strict guidelines would want your mortgage payment to be under $2,800. They would also want your total monthly debts to stay under $3,600. If you have a high car payment, your buying power drops because that debt eats into your 36% allowance.

What goes into your monthly payment

Many new buyers only look at the principal and interest payment. However, your monthly check to the bank includes several other items. In the real estate industry, this is known as PITI:

• Principal: The portion of the payment that pays down your actual loan balance.
• Interest: The cost of borrowing the money. In the early years of a 30-year mortgage, most of your payment goes toward interest.
• Taxes: Property taxes are collected by your local government to fund schools and services. These vary widely by location. Our calculator defaults to a national average of 1.1%, but you should look up the specific tax rate for your target neighborhood.
• Insurance: Homeowners insurance protects your property against damage. Lenders require this to protect their investment.

Our calculator also factors in Private Mortgage Insurance (PMI) and HOA fees. PMI is usually required if your down payment is less than 20% of the home price. HOA fees are paid to Homeowners Associations in condos or planned communities.

Things that change your buying power

You can adjust the inputs in the calculator to see how different factors change your result. Here is a quick look at what influences the bottom line the most:

• Interest Rates: A 1% increase in interest rates can noticeably reduce your buying power. Higher rates mean higher monthly interest costs, leaving less room for the principal loan amount.
• The Down Payment: A larger down payment reduces the loan amount, which lowers your monthly payment. Crossing the 20% down payment mark also removes PMI, which frees up extra cash each month.
• Loan Term: A standard loan is 30 years. Choosing a 15-year term increases your monthly payment but saves you a massive amount in total interest over time.