Mortgage Affordability Calculator: How Much House Can You Afford?
A mortgage affordability calculator estimates the loan and purchase price supported by a monthly housing budget. It applies a front-end housing ratio and a total debt-to-income ratio, then subtracts taxes, insurance, HOA dues, and mortgage insurance before converting the remaining payment to principal.
Quick answer
The lower of your housing-ratio limit and total-debt limit sets the planning budget. Lenders use additional underwriting rules, so this is an affordability scenario rather than an approval.
At a glance
- What it calculates
- Estimate an affordable mortgage and home price from income, debts, housing costs, rate, and down payment.
- Who it is for
- US first-time and repeat buyers testing a price range before talking to a lender.
- Coverage
- United States (federal rules; state and local rules vary)
- Data and assumptions
- Front-end housing ratio and total debt-to-income limits you set, a fixed rate, and taxes, insurance, HOA and mortgage insurance entered as monthly amounts.
- Cost
- Free, no signup, calculations run in your browser
- Last reviewed
- 2026-07-09
Calculator
How to use this calculator
- Enter gross annual household income.
- Add monthly debt payments and planning ratios.
- Enter mortgage rate, term, and down payment.
- Estimate taxes, insurance, HOA dues, and mortgage insurance.
- Review the home-price scenario and stress-test higher costs.
Explanation
What it is
A mortgage affordability calculator estimates the loan and purchase price supported by a monthly housing budget. It applies a front-end housing ratio and a total debt-to-income ratio, then subtracts taxes, insurance, HOA dues, and mortgage insurance before converting the remaining payment to principal.
How it works
The calculator creates two monthly limits, chooses the lower one, subtracts non-principal housing costs, and converts the remaining principal-and-interest payment into a loan amount using fixed-rate amortization.
When to use it
Use it before house-hunting or a pre-approval conversation, so you shop within a price band you have tested yourself.
Limitations
- Lender overlays, credit score pricing and reserve requirements are not applied.
- Property tax and insurance rates vary widely by state, county and property.
- Program-specific rules for FHA, VA and USDA loans are not modelled.
Key terms
- Front-end ratio
- Housing costs divided by gross monthly income.
- Back-end ratio
- Housing plus recurring debt divided by gross monthly income.
- PITI
- Principal, interest, property taxes, and homeowners insurance.
- Mortgage insurance
- Coverage that may be required for certain loans or down-payment levels.
Formula
The calculator creates two monthly limits, chooses the lower one, subtracts non-principal housing costs, and converts the remaining principal-and-interest payment into a loan amount using fixed-rate amortization.
Worked example
With $100,000 income, $750 in monthly debt, conservative ratios, a 6.5% mortgage, and $950 of monthly taxes and other costs, the estimated purchase price depends heavily on the down payment and rate.
FAQ
How much house can I afford on $100,000 a year?
It depends on debts, rates, down payment, taxes, insurance, HOA dues, credit, and lender rules. This calculator turns those assumptions into a planning range.
What debt-to-income ratio do mortgage lenders use?
Limits vary by product and borrower. Common planning ratios are not universal approval standards, and automated underwriting may consider compensating factors.
Does affordability include property taxes and insurance?
Yes. Enter monthly estimates because these costs reduce the amount available for mortgage principal and interest.
Why does a higher mortgage rate reduce the price I can afford?
At a fixed monthly budget, a higher rate directs more payment to interest, so it supports a smaller principal balance.
Should I buy at the maximum amount shown?
Not necessarily. Leave room for maintenance, utilities, moving, savings, income changes, and goals that lender ratios do not measure.
How much house can I afford on $75,000 a year?
With a 28% housing ratio, $75,000 supports about $1,750 a month for housing. After typical taxes and insurance, that is roughly a $250,000 to $300,000 home at a 6.5% rate with 10% down, depending on your other debt payments.
Common mistakes
- Comparing a principal-and-interest payment with a full PITI budget.
- Using gross income while forgetting that lenders count required minimum debt payments.
- Treating the maximum affordable price as the recommended price.
- Ignoring student loan payments that count toward the back-end ratio.
Tips
- Enter the housing and total debt ratios your lender actually uses rather than accepting defaults.
- Include property tax, insurance, HOA and mortgage insurance, which can add hundreds a month.
- Test the affordable price one percentage point above today's rate.
- Leave room for maintenance and closing costs, which the ratios ignore.
Sources and editorial review
Educational estimates only; not personalized financial, tax, legal, lending, investment, or insurance advice.