Home Affordability Calculator

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Home Affordability Calculator

Find the most house you can afford from your income, debts and down payment, using the debt ratio rules lenders apply in the United States and Canada. Or enter a price and see whether your income qualifies, and by how much.

Ratio limits

Every figuretap a card to copy its value
Two sets of limits

Maximum price against income

What moves the price

Housing limit = front ratio × gross monthly income. Debt limit = back ratio × gross monthly income − other debt payments. The maximum housing payment is the smaller of the two. Price is solved exactly, because the loan payment, property tax and any mortgage insurance all grow with the price: housing cost = loan × payment factor + price × tax rate ÷ 12 + fixed costs. Loan payment = loan × r ÷ (1 − (1 + r) to the power −n). In Canada the payment used for the ratios is worked out at the stress test rate, with interest compounded semi annually. This is an estimate, not a pre approval: lenders apply their own rules, credit score and program limits. The CSV, image and printed report contain the values you entered, nothing preloaded.

How to use this tool

Choose the country, then find the most you can afford or check a price you have in mind. Enter gross income before tax, your monthly debt payments such as car loans, student loans and card minimums, the down payment, the rate and the term. Add the running costs: property tax, plus insurance and HOA fees in the US or heating and condo fees in Canada. The ratio limits are editable.

The input people most often get wrong is income. Lenders count gross income, so the take home figure on a pay stub understates it: entering $80,000 instead of $100,000 in the default case cuts the answer from $333,021 to $235,551. Debts are the required monthly payments, not balances, and rent and groceries are not counted. The property tax box is a percentage of the price, so 1 means 1%.

What the calculation is doing

A lender applies two tests to gross monthly income. The front end ratio limits the housing payment alone, classically to 28%. The back end ratio limits housing plus every other debt payment, classically to 36%. The tool finds how much housing payment each test allows, takes the smaller, and solves for the price whose payment equals it.

In the default case, $100,000 a year is $8,333.33 a month. The front end limit allows $2,333.33. The back end limit allows $3,000 less $800 of debts, which is $2,200. That is tighter, so $2,200 is the most housing can cost.

Housing means principal and interest, property tax, insurance, HOA fees and mortgage insurance under 20% down. Tax and mortgage insurance grow with the price, so the tool writes the cost as price × a + b, where a combines the loan payment factor and the tax rate and b is the fixed costs, then solves price = (limit − b) ÷ a exactly. Here a is 0.0061558 and b is $150, so the price is $333,021.79 before rounding down to a whole dollar.

Canada uses GDS for the front end test and TDS for the back end test, capped by CMHC at 39% and 44% for insured mortgages. Both are tested at a qualifying rate, the greater of your contract rate plus 2 points and 5.25%, and housing counts principal and interest, property tax, heating and half of any condo fees. By the usual convention fixed rate interest compounds semi annually. An optional switch adds the CMHC premium.

Two panels for a $100,000 income, $800 a month of debts, 20% down and a 7% rate over 30 years. The first shows one month of gross income, $8,333, as a bar split into $2,200 for housing, $800 of debts and $5,333 left over, with the front end limit of $2,333 and the back end limit of $3,000 marked, and the $2,200 housing payment split into $1,772 of principal and interest, $278 of tax and $150 of insurance, which carries a price of $333,021. The second shows how the maximum price moves: down $27,209 for a rate 1 point higher, down $16,245 for $100 a month more debt, down $67,687 for $5,000 a year more debt payments and up $48,735 for $10,000 more income.
The back end limit binds by $133 a month, so debts count dollar for dollar. Each $1 a month of payment carries about $162 of price here, so $100 a month of debt removes $16,245 and $5,000 a year removes $67,687.

What lenders test, and why the back end usually binds

Lenders do not ask what you would like to spend. They ask whether the payment fits inside a share of gross income. The CFPB's home loan toolkit, updated in July 2026, gives a rule of thumb of 28% of monthly income before taxes for the total home payment. HUD counselor material from April 2025 gives 28% for conventional and 31% for FHA housing ratios, with back end ratios that traditionally stopped at 36% and can reach 43% to 50%.

Fannie Mae's Selling Guide, dated April 2, 2025, allows 36% on the back end for manually underwritten loans, up to 45% with compensating factors, and 50% through its Desktop Underwriter. The CFPB replaced the fixed 43% limit for General QM loans with a price based test from July 1, 2021. So there is no single ceiling.

With ordinary consumer debts the back end usually binds. The two limits meet when monthly debts equal 8% of gross monthly income, the gap between 36% and 28%: $666.67 a month at $100,000 a year. Below that, debts cost nothing. Above it, each dollar of debt takes a dollar from housing. At $800 of debts the crossover income is $120,000.

Holding income at $100,000 with 20% down, the price is $354,681 with no debts or $400 a month, then $333,021 at $800, $268,041 at $1,200 and $138,082 at $2,000. Past $667, each $100 costs $16,245.

How debts, rates and down payments move the price

At the default settings one dollar of monthly payment carries $162 of price, which is 1 ÷ 0.0061558. So $100 a month of debt removes $16,245 and a $500 a month car payment removes $81,225.

Rate matters almost as much. With $100,000 of income, $800 of debts and 20% down, the price is $399,773 at 5%, $364,137 at 6% and $333,021 at 7%, so each point costs 8% to 9%. Terms of 15, 20 and 30 years give $255,484, $291,370 and $333,021, because a shorter term needs a bigger payment per dollar borrowed.

The down payment adds to the price without touching the payment limit: $271,539 at 5% down, $284,878 at 10% and $333,021 at 20%. The bigger step to 20% includes dropping the mortgage insurance the tool assumes below it, 0.5% of the loan a year, an editable assumption.

Taxes and insurance draw on the same limit, and tax grows with the price. A 2% property tax rate cuts the price to $293,314, $3,600 a year of insurance to $308,654 and $300 a month of HOA fees to $284,286.

The Canadian stress test and the down payment rule

In Canada the payment is tested at a higher rate than you will pay. OSFI lists the minimum qualifying rate for uninsured mortgages as the greater of the contract rate plus 2 points and 5.25%, on a page last modified January 29, 2026, and CMHC applies the same rule to insured mortgages. At a 4.5% contract rate the test rate is 6.5%. Below 3.25% it is 5.25%.

The default Canadian case has $100,000 of income, $500 a month of debts, 20% down, 4.5% and 25 years. The maximum price is $487,193 at the test rate and $573,389 at 4.5%, so the test removes $86,196, or 15%. The payment you would actually make is $2,713 a month including tax and heat, well under the $3,167 the TDS limit allows.

The minimum down payment can bind first. Canada.ca, on a page modified in October 2025, sets it at 5% of the first $500,000, 10% of the part up to $1.5 million and 20% at $1.5 million or more. With $20,000 saved the price is capped at $20,000 ÷ 0.05 = $400,000 whatever the income, which is why three of the Canadian links below show exactly that.

Under 20% down an insured mortgage adds a CMHC premium of 2.80%, 3.10% or 4.00% of the loan, plus 0.20% for a 30 year amortization, which is open only to first time buyers and buyers of new builds. Switching the premium on at $60,000 down lowers the maximum from $453,897 to $443,329.

Maximum price by income and down payment

US maximum price at $800 a month of debts, 7%, 30 years, 1% property tax and $1,800 of insurance, with mortgage insurance of 0.5% of the loan below 20% down. Each figure opens the calculator with those inputs.

Gross income a year5% down10% down20% down
$50,000$72,852$76,430$89,347
$75,000$172,195$180,654$211,184
$100,000$271,539$284,878$333,021
$125,000$366,468$384,469$449,444
$150,000$443,735$465,532$544,206
$175,000$521,003$546,595$638,968
$200,000$598,270$627,658$733,730
$250,000$752,805$789,784$923,255

Doubling income from $50,000 to $100,000 multiplies the 20% down price by 3.7, then from $100,000 to $200,000 by 2.2, because the fixed $800 of debts takes a smaller share of the larger income.

Qualifying is not the same as comfortable

The calculator answers what a lender's ratios allow, which is not the same as what is comfortable. The CFPB toolkit says a lender considers only whether you are able to repay, not whether you are comfortable repaying. The ratios use gross income, so they ignore income tax, childcare, saving and the cash you want left after closing. At the default limit, 36% of gross income is committed before a dollar of income tax comes out.

Treat the result as a ceiling and put your own budget underneath it. Rerun the tool with a higher rate, a shorter term or a bigger debt payment and see how far the number moves. The gap between the lender's price and the price your budget holds is the number that matters, and only you can fill it in.

A worked example you can check on paper

Take $100,000, $800 of debts, 20% down, 7% and 30 years, with 1% tax and $1,800 of insurance. Monthly income is 100,000 ÷ 12 = $8,333.33. Front end limit: 0.28 × 8,333.33 = $2,333.33. Back end limit: 0.36 × 8,333.33 = $3,000.00, less $800, which is $2,200.00. The smaller is $2,200.00.

The payment factor at 7% over 360 months is 0.0058333 ÷ (1 − 1.0058333 to the power −360) = 0.006653. Cost = price × (0.8 × 0.006653 + 0.01 ÷ 12) + $150 = price × 0.0061558 + $150. Setting that to $2,200.00 gives price = $2,050.00 ÷ 0.0061558 = $333,021.79, so $333,021.

Check it. Down payment 20% × $333,021 = $66,604.20 leaves a loan of $266,416.80. Payment = $266,416.80 × 0.006653 = $1,772.48. Tax = $333,021 × 0.01 ÷ 12 = $277.52. Insurance = 1,800 ÷ 12 = $150.00. Total $2,200.00, which is 26.4% of gross income and 36% with the debts.

Mistakes that catch people out

Entering take home pay. Lenders use gross income. Entering $80,000 instead of $100,000 gives $235,551, not $333,021, a loss of $97,470 of price.

Counting balances instead of payments. A $12,000 car loan counts as its required monthly payment, and a paid off loan counts as zero.

Treating 28 and 36 as universal. They are a rule of thumb. FHA benchmarks are 31 and 43 and CMHC insured limits are 39 and 44. Edit the limits to the ones your lender quotes.

Leaving out tax, insurance and fees. Zero property tax in the default case gives $385,163 instead of $333,021, an overstatement of $52,142.

Ignoring the stress test in Canada. A payment that fits at the contract rate can fail at the qualifying rate: $573,389 against $487,193 in the default case. The qualifying price is the one that counts.

Popular calculations

Each link opens the calculator with those figures filled in. The United States links use $800 a month of debts, 7% and 30 years unless stated. The Canadian links use $500 a month of debts, a 4.5% contract rate, 25 years and the CMHC premium switched on under 20% down.

United States: income and down payment

$60,000 income, $20,000 down: $125,444$60,000 income, $60,000 down: $166,861$80,000 income, $20,000 down: $201,365$80,000 income, $60,000 down: $247,006$100,000 income, $20,000 down: $277,285$100,000 income, $60,000 down: $313,067$120,000 income, $20,000 down: $353,205$120,000 income, $60,000 down: $388,987$150,000 income, $20,000 down: $441,779$150,000 income, $60,000 down: $477,561

United States: interest rate

5% on $100,000 income, 20% down: $399,7736% on $100,000 income, 20% down: $364,1377% on $100,000 income, 20% down: $333,021

United States: other debt payments

No other debts, $100,000 income: $354,681$400 a month of debts, $100,000 income: $354,681$1,200 a month of debts, $100,000 income: $268,041$2,000 a month of debts, $100,000 income: $138,082

United States: check a home price

$300,000 home on $100,000 income, 20% down: qualifies$400,000 home on $100,000 income, 20% down: $412.30 a month short

Canada: income and down payment

$60,000 income, $20,000 down: $216,593$60,000 income, $60,000 down: $259,161$80,000 income, $20,000 down: $310,616$80,000 income, $60,000 down: $349,324$100,000 income, $20,000 down: $400,000$100,000 income, $60,000 down: $443,329$120,000 income, $20,000 down: $400,000$120,000 income, $60,000 down: $538,084$150,000 income, $20,000 down: $400,000$150,000 income, $60,000 down: $659,397

Canada: contract rate

4% on $100,000 income, 20% down: $506,8504.5% on $100,000 income, 20% down: $487,1935% on $100,000 income, 20% down: $468,669

Canada: check a home price

$450,000 home on $100,000 income, 20% down: qualifies$550,000 home on $110,000 income, 20% down: $22.22 a month short

How this was checked

The maximum price was checked three ways. Each answer was put back through the payment formula, and the limiting ratio equalled its limit to the cent in 1,147 forward checks across 700 random cases, with the whole dollar price at most 1.1 cents under the limit. A brute force scan in $20 then $1 steps matched the algebra in all 1,267 comparisons, including 113 capped by the Canadian down payment rule and 7 at a mortgage insurance threshold. A month by month amortization of 120 loans ended at zero within a ten millionth of a dollar.

Published figures were reproduced too. The CFPB debt to income example, $1,500 of housing plus $500 of debts on $6,000, comes out at 25% for housing and 33% with all debts. The CFPB's $100,000, 4%, 30 year example gives $477.42, shown as $477 on the page, and $90,447.51 after five years against $90,448. The FCAC calculator page shows 300 payments of $581.60 and $74,481.50 of interest without listing its inputs. They match $100,000 at 5% compounded semi annually, where monthly compounding gives $584.59. A $1.2 million home needs $95,000 down, as in a TD Economics example.

The Canadian rules were checked on OSFI, CMHC, Canada.ca and Canada Gazette pages from 2025 and 2026, and the US ratios on CFPB, HUD and Fannie Mae pages from 2025 and 2026. CMHC's premium bands come from pages with no recent date, so treat that switch as an estimate and confirm it with a lender.

Common questions

How much house can I afford on $100,000 a year?

In the default case, with $800 a month of debts, 20% down, 7% and 30 years, about $333,021, limited by the back end ratio. With no other debts it is $354,681, limited by the front end ratio. In Canada, with $500 of debts, a 4.5% contract rate and 25 years, the stress test gives $487,193.

What do the 28 and 36 rules mean?

They cap housing at 28% of gross monthly income and housing plus all other debt payments at 36%. The CFPB calls 28% a rule of thumb, and FHA benchmarks are 31% and 43%.

What are GDS and TDS in Canada?

Gross debt service is the front end ratio: principal and interest, property tax, heating and half of any condo fees over gross income. Total debt service adds all other debt payments. CMHC caps them at 39% and 44% for insured mortgages.

Does the Canadian stress test still apply?

Yes, as far as sources checked on September 29, 2026 show. The OSFI page, last modified January 29, 2026, lists the greater of the contract rate plus 2 points and 5.25%. Rules have changed several times since 2024, so confirm with a lender.

Is the maximum price a pre approval?

No. It is an estimate from your inputs. A lender also weighs credit score, employment, savings after closing and the loan program, and may allow more or less.

What raises the maximum price the most?

At the default settings, $10,000 more income adds $48,735, one point off the rate $31,116, five more points of down payment $19,025 and $100 a month less debt $16,245. When the front end ratio binds, a smaller debt payment adds nothing.

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