How much can I borrow for a mortgage?

Lenders assess your income, existing debts, deposit size, interest rate, and loan term. In most countries, total debt repayments cannot exceed around 43-44% of gross monthly income. This calculator applies country-specific lending rules to estimate your maximum borrowing power.

What is a debt-to-income ratio?

Your debt-to-income (DTI) ratio is your total monthly debt payments divided by gross monthly income, expressed as a percentage. Most lenders require a back-end DTI below 43-44%, though FHA loans in the US may allow up to 57% for well-qualified borrowers.

How does my deposit or down payment affect how much I can borrow?

A larger deposit reduces the loan amount needed and may qualify you for better rates. In most countries, a deposit below 20% triggers mortgage insurance — PMI in the US, LMI in Australia, and CMHC insurance in Canada — which adds to your monthly costs.

Does this calculator include a stress test?

Yes. UK, Australian, and Canadian calculations include a serviceability stress test that assesses your affordability at a rate higher than your actual rate. This is a regulatory requirement designed to ensure you can handle rate increases.

Can I borrow more with a co-borrower?

Yes. Adding a co-borrower typically allows lenders to combine both incomes, which can significantly increase the maximum loan. Their debts will also be included in the affordability assessment.

Loans

Loan Affordability Calculator

Find out how much you can borrow based on your income, debts, and deposit — using real lending rules for your country.

Country / Currency

Annual Gross Income ($)

Monthly Debt Payments ($/mo)

Car loans, student loans, credit cards, etc.

Down Payment ($)

Interest Rate (%)

Loan Term (years)

Annual Property Tax Rate (%)

US average ~1.1%. Varies widely by state.

Annual Home Insurance Rate (%)

Typically 0.5–1% of home value annually.

Maximum Loan

—

Max Property Price

—

Monthly P&I Payment

—

Lending Method:

Item	Monthly Value
Principal & Interest	—
Est. Property Tax	—
Est. Home Insurance	—
Other Debt Payments	—
Total Monthly Obligations	—
Back-End DTI / TDS Ratio	—
Loan-to-Value (LTV)	—
Deposit / Down Payment	—

This calculator provides an estimate only. Actual borrowing limits depend on your credit score, lender policies, property type, and costs not captured here. Always consult a qualified mortgage broker or financial adviser before making decisions.

How It Works

Maximum Monthly Payment

Your maximum allowable monthly mortgage payment is derived from your gross income using your country's debt ratio limits (DTI, GDS/TDS, or LTI), minus any existing monthly debt payments.

Stress-Tested Rate (UK / AU / CA)

UK, Australian, and Canadian lenders must assess affordability at a rate higher than your actual rate (typically rate + 2–3%). The calculator applies this regulatory buffer to produce a realistic estimate.

Maximum Loan (Reverse Amortization)

Using the reverse amortization formula, we solve for the largest principal where monthly repayments stay within your maximum allowable payment at the assessment rate.

P = PMT × [(1+r)^n − 1] / [r(1+r)^n]

Maximum Property Price

Maximum property price = maximum loan + your deposit. Monthly repayments displayed in the results are then recalculated at your actual (not stressed) interest rate.

Country	Primary Affordability Rule	Stress Test Rate
🇺🇸 US	43% back-end DTI / 28% front-end PITI	Qualifying rate (no mandatory buffer)
🇬🇧 UK	4.5× loan-to-income cap (FCA)	Contract rate + 3% (Bank of England)
🇦🇺 AU	Net income serviceability (HEM benchmark)	Contract rate + 3% (APRA)
🇨🇦 CA	GDS ≤ 32% / TDS ≤ 44%	Higher of 5.25% or rate + 2% (OSFI B-20)

Frequently Asked Questions

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