How Much Mortgage Can I Afford?

The quick answer to this question is around 4.75 times your income. Multiply your annual income by 4.75, and you will roughly get the amount you can borrow as a mortgage.

However, the real answer is much more complex.

“How much mortgage can I afford?” is a question almost all first-time buyers and home movers in the UK have in their minds.

In 2026, the average mortgage size in the UK will have risen to £260,000. However, the average salary in the country is around £38,000.

Filling this gap requires an understanding of the ongoing lending rules, borrowers’ circumstances and opportunities for homebuyers.

This guide not just answers the question, “How much mortgage can I afford?” It explores mortgage affordability in the UK’s property market, along with lending rules and hard math.

The two questions that confuse most homebuyers

Most homebuyers in the UK assume that “How much mortgage can I afford?” and “How much money can I borrow?” are the same questions.

This is not the case. While you answer the first question, the lender answers the second.

The amount you can borrow strictly depends on the property you want to buy, your income, your deposit and your credit score. This amount is generally higher than the amount of mortgage you can afford.

Your affordability takes a lot more into consideration, such as your lifestyle, savings, expenses apart from buying the house, and more.

The standard UK affordability formula

Most lenders in the UK focus on the borrower’s annual income and loan-to-income (LTI) ratio while calculating affordability. The loan-to-income (or debt-to-income) ratio shows the percentage of your income you use to pay off your existing debts. A low LTI shows better financial stability, increasing your chances of getting a good mortgage deal.

Most mortgage lenders use the income multiple of 4.5x to calculate affordability. This helps them assess risk and ensure that the loan is manageable. While 4.5x to 4.75x is the standard lending, now many lenders in the UK can also go up to 5x to 6x of income as mortgage.

The latest rule changes have just made borrowing a little easier. The FCA rule change in 2025 relaxed the stress rate cap that was compulsory for lenders. Earlier, lenders would test whether the borrowers could afford an interest rate of 7% or 8%. Borrowers in 2026 need not go through these tests.

How do mortgage lenders calculate your mortgage lending?

This is how lenders answer your question, “How much mortgage can I afford?”

Borrowers need to pass through these stages to become eligible:

1. Income Assessment: The lender adds up your annual salary, along with bonuses and other income you may have.
2. Calculating Commitments: They deduct financial commitments like loans, credit cards, and other lifestyle costs.
3. Loan to value and deposit: The lender will now calculate your property price minus your deposit or equity which gives them loan to value percentage. More the deposit higher the lending amount.
4. Affordability Stress Test: While the 7% or 8% limit is not mandatory, a lender will check if you can survive a mortgage rate increase.
5. Credit Check Filter: They will conduct credit checks, get your credit score. Bear in mind this does not decide your borrowing amount but does affect if lender will accept you and your mortgage rate you could get.

Income multiples by lenders

Different mortgage lenders use different income multiples along with special lending criteria.

The table below shows key mortgage lenders on high street, their standard multiples, boost multiples, and criteria which may subject to change.

What income do mortgage lenders actually count?

Mortgage lenders, do not consider all income as valid for an mortgage application. Also, different incomes have different weightage in approving your application.

• Basic salary: 100% (the most common and certain)
• Guaranteed bonuses: 100% with 2 years history.
• Commission or variable bonus: 50%- 60% (lenders often take this on 3 months average.)
• Second job: 0% to 100% (most mortgage lenders require at least 12 months of work record)
• Child benefit/UC: Depends on the lender.

Which outgoings reduce your borrowing capacity?

Mortgage lenders focus on your loan-to-income ratio while analysing your application. Your debt can reduce your borrowing capacity.

So, how much?

As of 2026, it is safe to say that every £100 of monthly debt reduces your total mortgage capacity by £12,000 to £15,000.

Lenders today also look for arrangements like “Buy Now Pay Later” on your credit report or your mobile contract payments. These commitments may also count as monthly debts.

The impact of the deposit on your borrowing amount

When you pay a bigger deposit, the LTV reduces. This increases your chances of getting a better mortgage deal. Lenders in the UK have dedicated LTV bands in multiples of 5%, such as 70%, 75%, 80%, 85%, and so on.

When you make a bigger deposit, you can cross to a lower LTV band. This automatically improves your stress test performance, letting you borrow more at a better mortgage rate.

The hidden affordability lever of the mortgage term

Your mortgage term is the time period of your mortgage. If you want to increase your mortgage affordability, you can go for a longer term. A longer mortgage term for the same amount automatically reduces monthly payments.

Suppose you take a £250,000 mortgage. Now, with the same income and interest, your borrowing capacity will be different for 25-year and 35-year mortgage terms. This is because your monthly payment for:

• A 25-year term will be £1,460, and
• A 35-year term will be £1,190.

While the standard mortgage term in the UK is 25 years, 30, 35, and 40 years mortgage are getting increasingly common nowadays. While longer terms increase your borrowing capacity, know that your total interest will also increase. Also, you stay in debt for a longer time.

Many lenders also have a cap on the borrower’s maximum age at the end of the term. While some lenders are more lenient than others, the age is generally 70 to 75 years.

How your credit score affects your borrowing capacity

Your credit score affects your mortgage interest and your approval chances. This can also affect the income multiple the lender uses.

A high credit score can give you access to most high street banks, including those that offer income multiples as high as 5.5x to 6x. A poor credit score will have the opposite impact on your mortgage affordability, as your lender will not accept your application due to poor credit, irrespective of how high your income is.

Mortgage affordability for joint mortgages

Joint mortgage applications increase affordability as people combine income. However, they also combine debts. If one of the partners has a debt, it can also drag an otherwise solid application down. Most mortgage lenders allow 2 joint applications, while some may extend up to 4 applicants.

Now that we’re already on joint mortgages, let us discuss how you can increase your affordability with JBSP (joint borrower sole proprietor) mortgages. They have helped many first-time buyers.

Here, your parents, family member or partner can apply for a joint mortgage, increasing your overall borrowing power. Only your name goes on the application, and you become the sole owner of the property.

Understanding self-employed affordability

Many mortgage lenders have become sole trader-friendly. Work with a mortgage broker to find deals suitable for self-employed mortgages in the UK.

Coming to affordability calculations, most lenders use Salary + Dividends for company director mortgage. A few of them may also use net profit, which is generally higher.

If sole trader then most lenders will work on average income for last 2 years, while some lenders even use latest year income for affordability.

In the case of contractor mortgage, lenders use the day rate formula (your day rate x 5 days x 46 weeks). As compared to standard accounts, this significantly increases a contractor’s affordability.

Know the affordability

Along with asking questions like, “How much mortgage can I borrow?” you should also know the common affordability myth.

Just because a lender is ready to mortgage certain sum, it doesn’t mean that you should take it all. Maxing out your affordability is never a good idea for long-term financial stability.

Working with Fee Free mortgage brokers like MariannaFS can help you to secure best mortgage deal suitable to you.

At MariannaFS, our team of independent mortgage brokers helps you find the most suitable mortgage deals. Our mortgage advisor will find you lenders who are offering high-income multipliers. They will also help you make your mortgage application and ensure that you make informed decisions in your mortgage journey. Strat talking to our team by calling 02080902043 or contacting us here.

Frequently Asked Questions

Can I get a mortgage with a £30,000 salary?

Yes, but you may be capped at around £135,000 to £165,000. Look for suitable first-time buyer schemes or search for properties that meet your budget needs.

Will a 5-year fix help me borrow more?

Yes, many lenders have more lenient stress tests for 5-year fixed mortgages. Borrowers can get as much as 10% more than a 2-year fixed mortgage on the same property.

Can student loans hold me back from getting a good mortgage?

Yes, student loans count as debt. Lenders will deduct it from your income, reducing overall borrowing capacity but some lender will ignore this too.