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Mortgage Affordability Calculator

Calculate how much home you can afford based on income and debts

Quick Overview
Who Should Use This

Prospective homebuyers in the early stages of home shopping, anyone who wants to know their realistic budget before talking to a lender, and financial planners helping clients.

Purpose

Calculate the maximum home price and loan amount you can afford based on gross income, monthly debts, and the 28/36 lender guideline — before you start house hunting.

Example

$95K income, $400/month car payment, $200/month student loans — can afford up to $385K home with 20% down at 6.75%, keeping total housing at 28% of income ($2,217/month).

Your Financial Profile

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💡 Rule of Thumb: Lenders use 28/43 rule. Housing ≤ 28% gross income, total debts ≤ 43% gross income.

For educational purposes only. These results are estimates. Always verify with your lender for accurate rates, fees, and payment figures.

What You Can Afford

Maximum Home Price

$0

Based on 28/43 rule

Maximum Monthly Payment

$0

Including taxes & insurance

DTI Analysis

Gross Monthly Income$0
Current Monthly Debts$0
Max Housing Payment$0
Front-End DTI (Housing)0%
Back-End DTI (All Debts)0%

Loan Details

Home Price$0
Down Payment$0
Loan Amount$0
Monthly P&I$0
Property Tax$0
Insurance$150
Total Monthly$0
How to Use

How to Use This Calculator

Find your home budget in 4 simple steps

1

Enter Your Income

Input your annual gross income — before taxes. Include all sources: salary, bonuses averaged over 2 years, and consistent overtime.

2

Add Monthly Debts

Enter all current monthly debt payments: car loans, student loan minimums, credit card minimums, personal loans. Do not include utilities or subscriptions.

3

Set Down Payment & Rate

Enter how much you have saved for a down payment and the current interest rate from your lender or pre-approval letter.

4

Review Your Budget

See your maximum home price, monthly payment breakdown, and DTI ratios. Aim for the comfortable range, not the maximum allowed.

How Mortgage Affordability Is Calculated

Lenders determine how much mortgage you qualify for using two key debt-to-income ratios. The front-end ratio (housing ratio) compares your proposed monthly housing payment — principal, interest, taxes, and insurance — to your gross monthly income. Most conventional lenders prefer this below 28%. The back-end ratio compares all monthly debt payments (housing plus car loans, student loans, credit cards) to gross income, with a typical ceiling of 43%.

The calculator uses the 28/43 rule as a starting point, but actual qualification depends on your credit score, down payment size, loan type, and lender's specific guidelines. Borrowers with excellent credit (740+) and substantial down payments often qualify at higher DTI ratios through automated underwriting systems.

What Counts in Your Housing Payment?

Your "PITI" payment — Principal, Interest, Taxes, and Insurance — is what lenders use for the front-end DTI. If your down payment is below 20%, PMI (Private Mortgage Insurance) is also included. HOA fees are factored in for the back-end calculation. These add-ons can significantly increase the true monthly cost of homeownership beyond the base P&I payment.

Comfortable vs. Maximum Affordability

There is an important distinction between what a lender will approve and what is financially comfortable. Lenders calculate the maximum you qualify for based on income and debts — they do not account for your savings goals, lifestyle expenses, childcare costs, or long-term financial plans.

  • Lender maximum: The highest loan a lender will approve based on DTI rules
  • Comfortable maximum: Typically 10%–20% below the lender's maximum — leaves room for savings, emergencies, and life changes
  • The 25% rule: Some financial advisors recommend keeping housing costs (PITI) at or below 25% of gross income for long-term financial health

How Interest Rates Affect Affordability

Interest rates have a dramatic impact on buying power. At 6%, a buyer with $5,000/month available for housing can afford approximately $830,000. At 7%, the same buyer can afford only $745,000. A 1% rate increase reduces buying power by roughly 10%–12%. This is why affordability shifts so dramatically with market rate changes.

Down Payment Strategy

A larger down payment reduces the loan amount, eliminates PMI (if reaching 20%), and lowers your monthly payment — all improving affordability. However, depleting savings for a larger down payment can leave you financially vulnerable. Most advisors recommend maintaining at least 3–6 months of expenses in reserve after closing.

Affordability Guide

How Much Can You Afford?

Understanding the 28/43 rule and mortgage qualification

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28/43 Rule

Front-end: Housing ≤ 28% gross income. Back-end: All debts ≤ 43% gross income. Lenders use the lower of the two to determine max loan.

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Income Requirements

$400K home, 20% down: Need ~$100K income. $300K home: ~$75K income. Rule: Annual income should be 3-4x home price for comfortable payment.

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Debt Matters

Every $100/mo in debts reduces buying power by $20K. Pay off car = gain $80K buying power. Student loans hit hardest (long-term debt).

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Down Payment Impact

20% down = no PMI, better rates, lower payment. 10% down = add PMI ($200/mo). 3.5% FHA = higher payments, MIP for life on some.

📈

Rate Sensitivity

1% rate increase = 10-15% less buying power. At 6% can afford $400K. At 7% only $350K. Rates matter more than down payment size.

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Comfortable vs Maximum

Lender says $400K max. Comfortable = $350K. Leave room for life, savings, emergencies. Max qualification is not recommended spending.

Common Questions

Affordability FAQ

Quick answer: $100K-120K depending on debts and down payment.

Detailed breakdown with 20% down ($80K):

Monthly costs on $320K loan at 7%:

  • P&I: $2,129
  • Property tax (1.2%): $400
  • Insurance: $150
  • Total: $2,679/month

Income needed (no other debts):

  • $2,679 ÷ 0.28 = $9,568/month
  • Annual: $114,816

With existing debts:

  • $500/mo debts = need $107K income
  • $800/mo debts = need $125K income
  • $1,200/mo debts = need $150K income

With 10% down ($40K):

  • Loan: $360K
  • P&I + tax + ins + PMI: $3,100/mo
  • Need $133K income (no debts)

With 3.5% FHA ($14K down):

  • Loan: $386K
  • Payment: $3,200/mo
  • Need $138K income

No! Here's why comfortable ≠ maximum:

Lender approves you for $400K home:

  • Payment: $2,800/month (including tax/ins)
  • 43% of your gross income
  • Feels like a lot every month

What lenders don't consider:

  • 401(k) contributions (15% = $1,000/mo)
  • Childcare ($1,200/mo)
  • Car insurance ($150/mo)
  • Food, gas, utilities ($1,000/mo)
  • Health insurance ($400/mo)
  • Life insurance, phone, etc ($200/mo)
  • Savings goals ($500/mo)
  • Total: $4,450/mo not in debt calculations!

Better approach - 25% rule:

  • Keep housing at 25% of gross income
  • $7,000/mo income = $1,750 housing max
  • Can afford $280K comfortably vs $400K stretched

Real example:

John makes $100K, approved for $450K

  • Payment: $3,200/month
  • After taxes: Take-home $6,200
  • After housing: $3,000 left
  • After 401k, insurance, car: $1,500
  • For everything else: Tight!

John buys $350K instead

  • Payment: $2,500/month
  • Take-home: $6,200
  • After housing: $3,700 left
  • Can save, travel, enjoy life

Realistic range: $140K-180K depending on debts.

$50K income breakdown:

  • Gross monthly: $4,167
  • Max housing (28%): $1,167/month
  • Max total debts (43%): $1,792/month

No existing debts, 20% down:

  • Can afford: ~$180K home
  • Down payment: $36K
  • Monthly: $1,150 (P&I, tax, insurance)

With $300/mo debts:

  • Available for housing: $1,492 - $300 = $1,192
  • Can afford: ~$140K home
  • Down payment: $28K
  • Monthly: $1,100

With FHA (3.5% down):

  • Can afford: ~$160K
  • Down payment: $5,600 (much more accessible!)
  • Monthly: $1,400 (higher due to PMI)

Challenges at $50K income:

  • Tight budget for maintenance
  • Hard to save emergency fund
  • Little room for income disruption
  • Consider waiting until $60K+ income

Yes, but with conditions - must be consistent:

What lenders will count:

1. Guaranteed overtime (2+ year history):

  • Must show on tax returns
  • Average last 2 years
  • Example: $15K overtime annually = $1,250/mo extra

2. Regular bonuses (2+ year history):

  • Annual bonus: Average of last 2 years
  • $10K bonus = $833/mo added to income
  • Must be continuing (get letter from employer)

3. Commission (2+ year history):

  • Average of past 2 years
  • If increasing: Use recent year
  • If declining: May not count or average lower

What lenders WON'T count:

  • One-time bonuses (signing, retention)
  • Overtime under 2 years
  • Irregular income
  • Expected raise (doesn't count until you have it)

Documentation needed:

  • Last 2 years W-2s
  • Last 2 years tax returns
  • YTD paystubs
  • Employer letter (confirming continuation)

Example approval:

Base salary: $60K

  • Overtime last 2 years: $12K, $15K
  • Average: $13.5K = $1,125/mo
  • Lender income: $60K + $13.5K = $73.5K
  • Qualifies for $280K vs $230K on base alone
  • Gain: $50K more buying power

Yes, but lenders are conservative - expect 75% rule:

Conventional loans:

  • Can use 75% of projected rent
  • $2,000/mo rent = $1,500 counts toward income
  • Must provide lease or appraisal of rent value
  • If negative (rent < mortgage), counts against you

FHA loans:

  • More strict: Often require 2-year history as landlord
  • First-time investors: Hard to use rental income
  • Exception: Duplex (living in one unit)

VA loans:

  • Similar to conventional (75% rule)
  • Must have 6 months reserves (PITI)

Example scenarios:

Scenario A: Buying duplex, living in one unit

  • Rent other unit: $1,500/mo
  • Lender counts: $1,125/mo income
  • Your mortgage: $2,800/mo
  • Net cost to you: $1,675/mo
  • Easy to qualify!

Scenario B: Buying single-family rental

  • Projected rent: $2,000/mo
  • Lender counts: $1,500/mo income
  • Need to qualify for $2,200 payment + $1,500 "income"
  • Net: Must qualify as if payment is $700/mo
  • Plus: Show reserves for both properties

First rental property tips:

  • Buy duplex/triplex, live in one unit (easiest)
  • Or: Qualify on your income alone
  • After 2 years rental history: Much easier to expand

Combining incomes is powerful - but combines debts too:

Both on the loan (recommended if both have good credit):

Advantages:

  • Combined incomes = much more buying power
  • Both build credit history
  • Both have ownership rights
  • Stronger application

Disadvantages:

  • Both debts count (his student loans + her car)
  • Lender uses lower credit score for rate
  • Both responsible for payment

Example: Combined is better

Person A: $70K income, 780 credit, $200/mo debts
Person B: $60K income, 740 credit, $400/mo debts

Separate (A only):

  • Income: $70K
  • Can afford: $280K
  • Rate: 6.5% (780 credit)

Combined:

  • Income: $130K
  • Debts: $600/mo
  • Can afford: $420K
  • Rate: 6.75% (lower credit score applies)
  • Gain: $140K more buying power, worth 0.25% rate hit

When to keep separate:

Person A: $90K income, 800 credit, $0 debts
Person B: $45K income, 620 credit, $1,000/mo debts

A only:

  • Can afford: $380K
  • Rate: 6.25%

Combined:

  • Income: $135K
  • Debts: $1,000/mo
  • Can afford: $350K (debts kill it)
  • Rate: 7.5% (bad credit)
  • Better: Use A only, refinance later when B's credit improves