Buying a home is one of the biggest financial commitments you’ll ever make. Whether you’re a first-time buyer or planning to move home, one question almost everyone asks is:
“How much mortgage can I actually afford?”
The answer isn’t as straightforward as multiplying your salary by a number.
While your income is certainly important, mortgage lenders also consider your existing financial commitments, monthly spending, credit history, deposit size and even whether you could still comfortably afford repayments if interest rates increased.
Many people make the mistake of focusing only on how much they can borrow, when the more important question is how much they should borrow.
Borrowing the maximum available may leave very little room in your monthly budget for savings, emergencies or unexpected expenses. A mortgage should fit comfortably into your lifestyle—not become a source of financial stress.
Fortunately, understanding mortgage affordability isn’t as complicated as it might first appear. Once you know the factors lenders consider, you can begin planning more confidently and make informed decisions before speaking to a mortgage adviser or lender.
In this guide, we’ll explain:
- How mortgage affordability works
- How lenders calculate borrowing limits
- How salary affects borrowing
- How much first-time buyers may be able to borrow
- Why deposits matter
- How much you should realistically spend on a mortgage
By the end of this guide, you’ll have a much clearer understanding of how mortgage affordability works in the UK and the steps you can take to improve your chances of securing the right mortgage for your circumstances.
How Do Mortgage Lenders Calculate Affordability?
When you apply for a mortgage, lenders don’t simply look at your salary and decide how much to lend.
Instead, they carry out what’s known as an affordability assessment.
This assessment is designed to answer one simple question:
Can you comfortably afford the mortgage now and in the future?
To answer this, lenders review several areas of your finances.
Your Income
Your annual income is usually the starting point.
For employed applicants this may include:
- Basic salary
- Guaranteed overtime
- Bonuses (depending on the lender)
- Commission
- Regular allowances
If you’re self-employed, lenders may instead look at:
- Company accounts
- SA302 tax calculations
- Tax returns
- Average profits over recent years
Some lenders also consider additional sources of income, such as rental income or certain benefits, although this varies.
Existing Financial Commitments
Your current debts reduce the amount of disposable income available for mortgage repayments.
Lenders may consider:
- Credit cards
- Personal loans
- Car finance
- Buy Now Pay Later agreements
- Student loan repayments
- Existing mortgages
This doesn’t necessarily mean you’ll be declined—it simply affects affordability calculations.
Credit History
Your credit history provides lenders with an indication of how you’ve managed borrowing in the past.
They’ll usually look for things such as:
- Missed payments
- Defaults
- County Court Judgments (CCJs)
- Bankruptcy history
- Existing credit utilisation
Having a good credit history doesn’t guarantee approval, but it can improve the range of mortgage products available to you.
Monthly Living Expenses
Mortgage providers also consider your regular spending.
Typical expenses include:
- Household bills
- Council Tax
- Food shopping
- Travel costs
- Childcare
- Insurance
- Existing subscriptions
- Other financial commitments
This helps lenders determine whether you’ll still have enough money available after making your mortgage repayments.
Interest Rate Stress Tests
Mortgage lenders also consider what might happen if interest rates increase in the future.
Even if today’s mortgage payments appear affordable, lenders often test whether you could still manage repayments if rates were higher.
This is one reason why the amount you’re approved to borrow may be lower than expected.
How Much Mortgage Can I Afford Based on My Salary?
Salary is usually the biggest factor influencing how much you may be able to borrow.
Many UK lenders may offer somewhere between four and five times your annual income, although this isn’t guaranteed and varies between lenders.
The following table provides rough examples only.
| Annual Salary | Approximate Borrowing |
|---|---|
| £25,000 | £100,000 – £125,000 |
| £30,000 | £120,000 – £150,000 |
| £35,000 | £140,000 – £175,000 |
| £40,000 | £160,000 – £200,000 |
| £45,000 | £180,000 – £225,000 |
| £50,000 | £200,000 – £250,000 |
| £60,000 | £240,000 – £300,000 |
| £75,000 | £300,000 – £375,000 |
Remember that these figures are only estimates.
Someone earning £40,000 with no debts and an excellent credit history may be able to borrow more than someone earning £50,000 who has significant financial commitments.
Example Mortgage Affordability Scenario
Let’s look at a simple example.
Sarah
Sarah earns £40,000 per year.
She has:
- A 10% deposit saved.
- No outstanding loans.
- A good credit score.
- Stable full-time employment.
- Low monthly expenses.
Based on these circumstances, Sarah may be able to borrow somewhere between £160,000 and £200,000, depending on the lender and affordability assessment.
If Sarah wanted to purchase a home costing £220,000, she would need:
- Property price: £220,000
- Deposit (10%): £22,000
- Mortgage required: £198,000
This falls within the affordability range for many lenders, although approval would always depend on individual circumstances.
How Much Can a First-Time Buyer Borrow?
Being a first-time buyer doesn’t automatically mean you’ll be able to borrow more—or less.
Mortgage lenders generally assess first-time buyers using the same affordability criteria as existing homeowners.
They’ll still consider:
- Your income
- Existing debts
- Credit history
- Deposit size
- Employment stability
- Monthly spending
However, many first-time buyers benefit from government schemes or lender products designed specifically for those entering the property market.
Saving a larger deposit and maintaining a good credit history can often improve the range of mortgages available.
If you’re buying with a partner, both incomes are usually considered, which may increase your borrowing potential.
How Big a Mortgage Should I Get in the UK?
One of the biggest mistakes buyers make is assuming they should borrow the maximum amount a lender is willing to offer.
While it can be tempting to increase your budget, it’s worth remembering that a mortgage is a long-term financial commitment.
Instead of asking:
“What’s the biggest mortgage I can get?”
Ask yourself:
- Will I still be comfortable if interest rates increase?
- Can I continue saving every month?
- Do I have enough money left for emergencies?
- Can I still afford holidays and other lifestyle goals?
- Would I cope if my income temporarily reduced?
A mortgage should support your lifestyle—not limit it.
Many homeowners deliberately borrow less than the maximum available because it provides greater financial flexibility in the years ahead.
How Much Can I Spend on a Mortgage?
Rather than focusing purely on borrowing limits, think about your overall monthly budget.
Owning a home involves much more than simply making a mortgage repayment.
You’ll also need to budget for:
- Council Tax
- Gas and electricity
- Water bills
- Home insurance
- Broadband
- Home maintenance
- Service charges (if applicable)
- General repairs
These ongoing costs should all be considered when deciding how much you can comfortably afford to spend on your mortgage.
How Much Can I Afford to Spend on a Mortgage?
One of the most common misconceptions among home buyers is believing that if a lender is willing to lend a certain amount, it’s automatically the right amount to borrow.
In reality, there’s an important difference between:
- How much you can borrow
- How much you can comfortably afford
Choosing a mortgage that leaves little room in your monthly budget can make everyday life more stressful, particularly if unexpected expenses arise.
A good mortgage should allow you to continue enjoying your lifestyle while still leaving room to save for the future.
When deciding how much you can comfortably spend each month, consider all of your regular expenses, including:
- Household bills
- Food shopping
- Council Tax
- Insurance
- Childcare
- Fuel or public transport
- Entertainment
- Holidays
- Pension contributions
- Emergency savings
Remember that home ownership also comes with maintenance costs. Boilers break down, roofs need repairs and appliances eventually need replacing.
Leaving some financial breathing room can help you deal with these unexpected costs without relying on credit.
Why Your Deposit Matters
Your deposit plays one of the biggest roles in determining your mortgage options.
The more money you can put down upfront, the less you’ll need to borrow.
A larger deposit may also unlock lower interest rates and a wider choice of mortgage products.
5% Deposit
Many lenders now offer mortgages with a 5% deposit.
Advantages:
- Enter the property market sooner
- Lower amount of savings required
Disadvantages:
- Higher monthly repayments
- Fewer mortgage products
- Higher interest rates
10% Deposit
A 10% deposit is often seen as a good balance between affordability and flexibility.
Benefits include:
- More mortgage choices
- Better interest rates
- Lower monthly repayments than a 5% deposit
15%–20% Deposit
Saving a larger deposit usually improves your loan-to-value ratio.
Benefits often include:
- Lower interest rates
- Reduced monthly repayments
- Lower overall borrowing costs
- Greater lender choice
Although saving a larger deposit may take longer, the long-term savings can be significant.
What Is Loan-to-Value (LTV)?
Loan-to-Value (LTV) is one of the most important terms you’ll come across when applying for a mortgage.
It compares the amount you borrow with the property’s value.
For example:
Property price:
£250,000
Deposit:
£25,000
Mortgage:
£225,000
Your LTV would be:
90%
Generally speaking:
| Deposit | Loan-to-Value |
|---|---|
| 5% | 95% |
| 10% | 90% |
| 15% | 85% |
| 20% | 80% |
Lower LTV mortgages often qualify for more competitive interest rates.
How Interest Rates Affect Monthly Repayments
Interest rates have a significant effect on the amount you’ll repay each month.
Even a difference of one percentage point can noticeably increase your repayments.
For illustration only:
| Interest Rate | Approximate Monthly Payment* |
|---|---|
| 3% | £948 |
| 4% | £1,056 |
| 5% | £1,169 |
*Example based on a £200,000 repayment mortgage over 25 years.
Although these figures are estimates, they demonstrate why affordability checks are so important.
When comparing mortgage deals, don’t just look at the interest rate—also consider:
- Arrangement fees
- Product fees
- Early repayment charges
- Incentives
- Overall borrowing costs
Buying Alone vs Buying Together
Many people purchase a property with a partner.
A joint mortgage may increase your borrowing potential because lenders usually consider both incomes.
Benefits include:
- Greater borrowing power
- Shared monthly repayments
- Easier to save a larger deposit
However, both applicants are jointly responsible for the mortgage.
If one person cannot make repayments, the other remains legally responsible for the full amount.
It’s important to discuss finances openly before committing to a joint mortgage.
Ways to Improve Your Mortgage Affordability
If you’re planning to buy within the next year or two, there are several practical steps you can take to improve your mortgage application.
Save a Larger Deposit
A larger deposit often improves the mortgage products available and may reduce your monthly repayments.
Reduce Existing Debt
Paying down credit cards, loans and finance agreements can improve your affordability assessment.
Improve Your Credit Score
Simple steps include:
- Paying bills on time.
- Registering on the electoral roll.
- Keeping credit utilisation low.
- Avoiding missed payments.
Avoid Applying for New Credit
Applying for loans or finance shortly before a mortgage application may affect your credit profile.
Where possible, avoid taking on additional borrowing before applying.
Increase Your Income
Salary increases, promotions or additional sources of income may positively affect affordability.
Build Emergency Savings
Owning a home often comes with unexpected costs.
Having several months’ worth of savings can provide valuable peace of mind after moving.
Use a Mortgage Calculator Before Applying
Mortgage calculators provide an easy way to explore different borrowing scenarios before speaking to a lender.
You can compare:
- Monthly repayments
- Interest rates
- Mortgage terms
- Deposit sizes
- Overpayment options
Understanding these figures in advance can help you make more informed decisions and avoid surprises later.
Related App
UK Mortgage Calculator
If you’re planning to buy a property or remortgage, the UK Mortgage Calculator app can help you explore different mortgage scenarios in seconds.
Features include:
- Mortgage repayment calculator
- Interest-only and repayment comparisons
- Mortgage term comparisons
- Overpayment calculations
- Total interest breakdown
- Easy-to-understand monthly repayment estimates
Whether you’re a first-time buyer or an existing homeowner, it’s a practical tool for understanding how different mortgage choices affect your finances.
Frequently Asked Questions
How much mortgage can I get on a £30,000 salary?
Many lenders may offer approximately £120,000–£150,000, depending on your financial circumstances and affordability checks.
How much mortgage can I get on a £40,000 salary?
Borrowing around £160,000–£200,000 is common, although this varies between lenders.
Can I get a mortgage with a 5% deposit?
Yes. Some lenders offer mortgages with a 5% deposit, although interest rates may be higher.
Does bad credit stop me getting a mortgage?
Not always.
Some lenders specialise in applicants with less-than-perfect credit histories, although the products available may differ.
Can self-employed people get a mortgage?
Yes.
Lenders will usually ask for additional evidence of income, such as tax returns or company accounts.
Can I include overtime or bonuses?
Some lenders accept overtime, commission or bonuses as part of your income, although policies vary.
How much deposit should I save?
Many buyers aim for at least 10%, although larger deposits often improve mortgage options.
Can I overpay my mortgage?
Many mortgage products allow overpayments, although some have annual limits or early repayment charges.
What happens if interest rates increase?
Higher interest rates generally increase monthly repayments, particularly once a fixed-rate period ends.
Should I borrow the maximum offered?
Not necessarily.
Choosing a mortgage that comfortably fits your budget is often the safer long-term decision.
Disclaimer
This article is intended for general informational purposes only and should not be considered financial, legal or mortgage advice.
Mortgage lending criteria, affordability assessments and interest rates vary between lenders and may change over time. Before making any financial decisions, consider speaking with a qualified mortgage adviser or independent financial adviser.
Final Thoughts
Understanding mortgage affordability is about much more than calculating how much you can borrow. A suitable mortgage should support your long-term financial wellbeing, allowing you to comfortably manage repayments while still saving for the future and enjoying your lifestyle.
By taking time to understand how lenders assess affordability, improving your financial position before applying and comparing different mortgage scenarios, you’ll be in a much stronger position to choose a mortgage that works for you—not just today, but for many years to come.
Whether you’re buying your very first home or planning your next move, careful preparation can make the process smoother, less stressful and more financially rewarding.
Before applying for a mortgage, it’s worth exploring different repayment scenarios using a mortgage calculator so you can see how loan amounts, interest rates and mortgage terms affect your monthly budget. A little planning today can help you make more confident decisions tomorrow.
