Your Estimated Mortgage Affordability
Estimated borrowing range
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Key figures
Affordability meter
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Zones are based on the share of estimated take-home pay used by total housing costs: mortgage payment, property tax, insurance, HOA or service charge, and maintenance.
How much can I borrow on my salary?
This is a simple income-multiple illustration only. Actual borrowing capacity depends on your debts, expenses, credit profile, deposit size, property type, and the country-specific criteria of the individual lender. The multiple is editable under Advanced inputs.
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Plain-English explanation of your result
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Once you know roughly what you can afford, the next question is usually how quickly you could pay it off. You can model extra repayments on the same mortgage with the CalcNest Mortgage Overpayment Calculator.
What-if scenario lab
| Scenario | Estimated borrowing | Home price | Monthly payment | Total housing cost | Money left each month | Affordability status |
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Interest rate stress test
| Rate | Monthly payment | Total housing cost | Money left each month | Affordability status |
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Debt payoff impact
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Important: CalcNest provides estimates for educational and planning purposes only. Actual mortgage affordability and borrowing capacity depend on lender criteria, income verification, credit history, expenses, taxes, insurance, location, property type, loan program, and other factors, and these vary by country. This calculator is not a mortgage offer, approval, pre-approval, Decision in Principle, or financial advice.
Mortgage Affordability Calculator
How Much Mortgage Can I Afford?
There are two different questions hiding inside that sentence, and most calculators only answer the first one. The first is how much a lender might be willing to lend you, which is largely a function of your income, your debts, and the rules that lender applies. The second is how much you can comfortably carry every month once tax, insurance, service charges, maintenance, childcare, and normal living costs come out of your pay. Those two numbers are frequently thousands apart, and the gap is where most affordability stress comes from.
This calculator answers both separately, and then adds a third answer that almost nothing else on the web gives you: if you already have a specific home price in mind, it works backward and tells you what income and deposit that price would realistically need. If you already know the loan amount and just want a monthly payment breakdown with taxes and insurance, the CalcNest Mortgage Calculator is the faster tool for that.
How Do I Use This Mortgage Affordability Calculator?
Step by step:
- Pick your country first. This is not cosmetic. It changes the calculation method, because the UK, US, and Canada assess affordability using genuinely different frameworks.
- Choose your mode. Leave it on “I know my income” to find out what you could borrow and afford. Switch to “I have a target home price” if you want to work backward from a price.
- Enter your gross household income and, separately, any additional income such as bonus, overtime, or rental income.
- Set the number of applicants. This is used to make the take-home pay estimate more realistic, since tax is assessed per person rather than per household.
- Enter your deposit. You can type an amount or a percentage; editing one updates the other.
- List your monthly commitments honestly. Debt payments, student loan repayment, childcare, essentials, and other spending. Understating these is the single most common way people get a flattering but useless result.
- Set the mortgage term and interest rate, then the running costs of the property: property tax or council tax, insurance, service charge or HOA fee, and maintenance.
- Open Advanced inputs if you want to change the assumptions. The income multiple, the comfort thresholds, the DTI or GDS/TDS ceilings, and the stress test uplift are all editable there.
- Read the three results together: the comfortable estimate, the indicative maximum, and the affordability meter. Then use the what-if table and rate stress test to see how much this scenario could absorb before it breaks.
- Copy the scenario link if you want to save it or send it to a partner or broker. The link carries your inputs; nothing is stored anywhere.
How Much Mortgage Can I Get Based on My Salary?
In the UK, Australia, and New Zealand the starting point is usually an income multiple. Historically that has sat somewhere around four to four and a half times income, sometimes higher for high earners or certain professional roles, sometimes lower where commitments are heavy. So a household on 55,000 might see an indicative figure somewhere between roughly 220,000 and 247,500 before anything else is considered.
The important word is “before”. That multiple is a ceiling, not a promise. Lenders then run an affordability assessment against your actual committed spending, and a household with significant childcare costs and car finance can end up well below the multiple. This tool shows the multiple explicitly so you can see it, then shows the budget-based figure next to it so you can see which one is actually constraining you.
What Salary Do I Need for a Specific Mortgage Amount?
This is what reverse mode is for. Rather than reading a fixed worked example about a 250,000 mortgage that assumes a deposit and rate you do not have, you enter the price you are aiming at, the deposit you expect to have, and your own rate and term. The tool then reports the annual income the selected country's method would require, the deposit needed at several loan-to-value thresholds, the monthly payment at that price, and whether the deposit you entered looks realistic for it.
Because the required income depends heavily on rate and term, the answer moves. A 250,000 purchase at 4.75% over 25 years demands a very different income from the same purchase at 6% over 20 years. Any article quoting a single salary figure for a single mortgage size is quietly hiding those assumptions.
How Mortgage Affordability Is Calculated
United Kingdom, Australia and New Zealand: income multiples plus an affordability check
Borrowing capacity is estimated as income multiplied by a multiple, then cross-checked against what your budget can actually support once tax, debts, childcare, essentials, and property running costs are removed. The lower of the two is the meaningful number. UK lenders also apply their own stress tests, so the rate they test you at may be higher than the rate you would actually pay.
United States: front-end and back-end DTI
American lenders work with debt-to-income ratios. The front-end ratio is your housing costs divided by gross monthly income, with a commonly cited ceiling around 28%. The back-end ratio is all your monthly debt payments including housing divided by gross monthly income, commonly capped somewhere between 36% and 43% depending on the loan program and compensating factors. Both are displayed in the results so you can see which one binds first. Note that DTI uses gross income, which is why a DTI-passing loan can still feel tight in practice.
Canada: GDS and TDS
Canadian lenders use two debt service ratios. GDS (Gross Debt Service) is the mortgage payment plus property tax plus heating plus half of any condo fees, divided by gross income, with a typical ceiling around 39%. TDS (Total Debt Service) is that same figure plus your other debt payments, with a typical ceiling around 44%. Both are shown by name. Canadian buyers with less than a 20% down payment also normally require mortgage default insurance, which is a separate cost this simplified tool does not add to the payment.
None of these three frameworks is a universal standard. They are simply how the market in each country tends to work.
Mortgage Affordability vs. Decision in Principle or Mortgage in Principle
These are not the same thing and confusing them causes real disappointment.
An affordability estimate, including this one, is an unverified calculation based on numbers you typed in. Nobody has checked your payslips, nobody has looked at your credit file, and no lender has committed to anything.
A Decision in Principle (also called an Agreement in Principle, Mortgage in Principle, or in North America a pre-qualification or pre-approval) is an indication from a specific lender, usually after at least a soft credit check, that they would consider lending you a stated amount. It is closer to reality but still conditional, and it can be withdrawn if the full application reveals something different.
The numbers commonly differ because a lender sees your credit history, verifies income differently, may treat bonus or self-employed income more conservatively, applies its own stress rate, and assesses the specific property. An affordability calculator has none of that information. Treat the calculator as a planning tool for narrowing your search, and the Decision in Principle as the first real checkpoint.
Can I Calculate My Mortgage Affordability Without a Calculator?
Yes, and it is worth knowing the arithmetic so you can sanity-check any tool including this one.
Income multiple route (UK/AU/NZ): multiply gross household income by 4.5 for a rough upper figure and by 4 for a more cautious one. Add your deposit to get an approximate property price.
DTI route (US): take gross monthly income, multiply by 0.28 for the maximum housing cost, then subtract monthly property tax, insurance, and HOA to find what is left for principal and interest. Repeat with 0.36 and also subtract your other debt payments; use whichever result is lower.
Budget route (any country): take your actual monthly take-home pay, subtract every committed cost including debts, childcare, and essentials, and treat no more than roughly 70% of what remains as available for total housing costs. This tends to produce the most honest number of the three.
The monthly payment itself follows the standard amortisation formula, where P is the loan, r the monthly interest rate, and n the number of monthly payments: M = P × [r(1+r)n] / [(1+r)n − 1].
Why Your Debts and Student Loan Repayments Affect How Much You Can Borrow
Every pound or dollar committed to a monthly repayment is money that cannot service a mortgage, and lenders model it that way. A 250 monthly car finance payment can reduce borrowing capacity by a surprisingly large multiple of itself, because the assessment is about sustainable monthly capacity rather than the size of the debt.
Student loans deserve their own field, which is why this calculator separates them. In the UK, Plan 2 and Plan 5 repayments are income-contingent deductions taken above a threshold, so they reduce take-home pay without behaving like conventional debt. In the US, income-driven repayment plans mean the monthly figure can differ enormously from what a standard amortisation of the balance would suggest, and how underwriters treat deferred or IDR loans varies by program. Either way, the monthly amount leaving your account is real, and leaving it out inflates your result.
How Your Deposit Affects Mortgage Affordability
A larger deposit does three things at once. It reduces the amount you need to borrow, it lowers your loan-to-value ratio, which can open up better pricing, and in several markets it can reduce or remove a mortgage insurance requirement. Use the deposit slider in the results to watch the loan amount, LTV, monthly payment, and achievable price move together.
What a deposit does not do is raise your income-based ceiling. If your borrowing is constrained by an income multiple or a DTI ratio rather than by cash, extra deposit increases the price you can reach but not the loan you can obtain.
Mortgage Affordability for Self-Employed Borrowers
Self-employed applicants are not assessed on turnover but on assessable income, and lenders disagree about how to define it. Some average the last two or three years, some take the most recent year, some take the lower of an average and the latest figure, and treatment of retained profits inside a limited company varies considerably.
This calculator takes a deliberately cautious position: when you select self-employed, it uses the lower of your stated average and your most recent year. If your income is rising, that will understate what a sympathetic lender might use. If your income is volatile, it is closer to how a cautious underwriter will see it. Most lenders also want to see at least two to three years of records, which is why the tool asks how long you have been trading.
What Happens If Interest Rates Rise?
The stress test table shows your current rate alongside increases of one, two, and three percentage points, with the monthly payment, total housing cost, remaining money, and affordability status at each. On a 25-year mortgage, a two-point rise typically adds a material amount to the monthly payment, often enough to move a scenario from the comfortable zone into the stretch zone.
This is an illustration, not a forecast, and it is not the specific stress test any particular lender uses. Its purpose is to show whether your plan depends on rates staying where they are. If your scenario only works at today's rate, that is useful information before you commit, particularly if your initial fixed period ends well before the mortgage does.
First-Time Buyer Schemes That Can Affect Affordability
Schemes generally help with the deposit rather than with income. A UK Lifetime ISA adds a 25% government bonus to eligible contributions within annual limits, which increases the cash you bring to the purchase. A Canadian First Home Savings Account offers tax advantages on money saved toward a first home. In the US, down payment assistance exists in many areas as grants, forgivable loans, or second liens, with widely varying income caps and conditions. Guarantee schemes are different again: they support lenders in offering higher loan-to-value products rather than giving you additional funds.
The calculator can model the effect of a bonus or an account balance on your deposit, but it cannot and does not assess your eligibility. Always check current scheme rules before relying on them.
Why the Mortgage You Can Borrow Isn't Always What You Can Afford
Lender assessments are built around whether you are likely to keep paying. They are not built around whether your life will still be enjoyable, whether you can keep saving, or whether you could survive a broken boiler and a car repair in the same month. Borrowing at your absolute maximum is legal, sometimes sensible, and often uncomfortable.
That is why this tool reports a comfortable figure alongside the indicative maximum, and why the affordability meter is based on take-home pay rather than gross income. The distance between those two numbers is your buffer.
Your Affordability Can Change Even If Your Salary Doesn't
Affordability is not a fixed property of your income. It moves when interest rates move, when you clear or take on debt, when you save more deposit, when you lengthen or shorten the term, and when the running costs of the specific property you are looking at differ from your assumptions. Two identical earners looking at two identical prices can reach different conclusions purely because one is buying a flat with a high service charge.
Extending the term lowers the monthly payment and can increase borrowing capacity, but it increases total interest paid over the life of the loan. That trade-off is worth modelling deliberately rather than accepting by default.
What Happens If Your Income Falls?
Any long-term commitment should be tested against a worse year, not just a good one. Redundancy, reduced hours, a lost contract, illness, or a partner stepping back from work all reduce household income while the mortgage payment stays exactly the same. As a general planning point rather than personal advice, many people find it useful to check whether a scenario would still function on a single income, or on a meaningfully reduced one, and to keep an emergency buffer of several months of essential outgoings in accessible savings.
You can model this directly here: reduce the income figure, recalculate, and see which zone the scenario lands in.
When you have a figure you are comfortable with, the natural next step is working out how quickly you could clear it. The CalcNest Mortgage Overpayment Calculator lets you model extra monthly or lump-sum repayments on the same mortgage and see the interest saved and the years removed from the term. For a plain walkthrough of the maths behind that, see this guide to calculating mortgage overpayments and what they save you.
Frequently Asked Questions
What is a mortgage affordability calculator?
A mortgage affordability calculator estimates how much you could borrow and how much you could comfortably repay, based on your income, deposit, debts, monthly expenses, interest rate, and mortgage term. It is a planning tool that produces an unverified estimate, not a lending decision or an offer.
How much mortgage can I afford?
It depends on two separate limits: the amount a lender's rules would permit, and the amount your monthly budget can sustain after tax, debts, childcare, essentials, and property running costs. The lower of those two is your realistic figure. This calculator shows both, plus a more conservative comfortable estimate, so you can see which limit is binding.
How much mortgage can I borrow based on my salary?
In the UK, Australia, and New Zealand a common starting point is around four to four and a half times gross household income, though the final figure is then reduced by your committed monthly spending. In the US and Canada the calculation is ratio-based rather than multiple-based, using DTI in the US and GDS and TDS in Canada.
What salary do I need for a mortgage of a specific amount?
Switch this calculator to “I have a target home price”, enter the price, your expected deposit, your interest rate, and your term. It works backward and reports the annual income the selected country's method would require, along with the deposit needed at several loan-to-value levels. The required salary changes significantly with the rate and term, so there is no single universal answer for a given mortgage size.
How does a deposit affect mortgage affordability?
A larger deposit reduces the amount you need to borrow, lowers your loan-to-value ratio, reduces the monthly payment, and in some markets can reduce or remove a mortgage insurance requirement. It does not increase the income-based ceiling on what you can borrow, so if income is your constraint, extra deposit raises the price you can reach rather than the loan you can get.
Does debt reduce how much mortgage I can get?
Yes. Monthly commitments such as loans, credit cards, and car finance reduce the income available to service a mortgage, and lenders factor them into affordability assessments directly. Because the assessment is based on sustainable monthly capacity, clearing a modest monthly payment can increase borrowing capacity by many times the payment itself.
Can self-employed people use a mortgage affordability calculator?
Yes. Select self-employed and enter your average income over the last two to three years, your most recent year, your lowest recent year, and how long you have been trading. This calculator conservatively uses the lower of your average and your most recent figure. Real lender treatment varies significantly, with some averaging multiple years and others using the latest year only.
What is the difference between a mortgage affordability calculator and a Decision in Principle?
An affordability calculator produces an unverified estimate from numbers you enter yourself. A Decision in Principle, also called an Agreement in Principle or a pre-approval, is an indication from a specific lender, usually following at least a soft credit check, that it would consider lending a stated amount. The figures often differ because a lender verifies income, reviews credit history, applies its own stress rate, and assesses the property.
Can I calculate mortgage affordability without a calculator?
Yes. For an income-multiple estimate, multiply gross household income by 4 and by 4.5 to get a range and add your deposit. For a US-style estimate, multiply gross monthly income by 0.28 for maximum housing costs, then subtract property tax, insurance, and HOA fees. For a budget estimate, subtract all committed monthly costs from take-home pay and treat about 70% of what remains as available for housing.
How does GDS and TDS affect mortgage affordability in Canada?
GDS, or Gross Debt Service, is the mortgage payment plus property tax plus heating plus half of any condo fees, divided by gross income, with a typical ceiling near 39%. TDS, or Total Debt Service, adds your other debt payments and typically has a ceiling near 44%. Whichever ratio is reached first limits your borrowing, and this calculator displays both by name.
What happens if interest rates rise?
Your monthly payment rises when your rate resets or your fixed period ends, while your income may not. The stress test in this calculator shows the payment, total housing cost, remaining monthly money, and affordability status at your current rate and at one, two, and three percentage points higher, so you can see whether the plan still works. It is an illustration rather than a prediction or a specific lender's test.
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