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Getting a mortgage

How much can you borrow?

By Marie Kemplay

Article 1 of 12

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How much can you borrow?

Find out how much a bank is likely to lend you for a mortgage and how the 'loan-to-value', or LTV, affects your deal. Plus, use our LTV calculator. 

Hoping to buy a property but not sure how much mortgage you'll be able to borrow?

This guide explains how mortgage lenders assess affordability, how loan-to-value ratios work, and how much lenders are likely to offer you.

If you'd like personal, impartial advice on how much mortgage you'll be able to borrow, call Which? Mortgage Advisers on 0808 252 7987.

Mortgage calculator: how much can you borrow? 

Bear in mind that a calculator only gives you a rough idea of how much you might be able to borrow. For an accurate answer, call Which? Mortgage Advisers on 0808 252 7987.

How do mortgage lenders decide how much you can borrow? 

The amount you're able to borrow from a mortgage lender will largely depend on how much you can afford to pay back. 

As a rule of thumb, banks and building societies will let you borrow up to four-and-a-half times the total income of you and anyone else you're buying with. Above this threshold, regulations are in place to limit borrowings.  

When deciding how much to lend you, a mortgage provider will do an 'affordability assessment'. Essentially, this means looking at the amount you typically earn in a month compared with how much you spend. 

Lenders are also interested in the types of things you spend your money on. Some expenses can be quickly cut back, while others are less flexible - a gym membership, for example, may be easy to cancel whereas childcare costs are likely to be fixed.

Your lender will ask about things such as: 


  • Regular income from paid work
  • Any benefits that you receive 
  • Income from other sources 


  • Debt repayments such as student loan or credit card bills
  • Regular bills such as gas and electricity 
  • Transport costs
  • Grocery costs
  • Spending on leisure activities

The lender will also compare what you say with recent bank statements and wage slips. See our 'Applying for a mortgage' guide for more detail on the documents you need for an application. 

Mortgage calculator: how much can you afford in monthly repayments? 

Click on the link below to download the Which? mortgage affordability calculator. This calculator will help you to figure out how much you can afford to spend on mortgage repayments each month, based on your monthly income and outgoings. 

How much mortgage can I afford?

What does 'LTV' mean and how does it affect your mortgage rate? 

The deals you're offered when applying for a mortgage will usually be affected by the loan-to-value ratio or 'LTV' - ie the proportion of the price that you're borrowing compared to how much you're putting in yourself.

For example, if you're buying a property for £200,000, putting in a £20,000 deposit and taking out a mortgage for the remaining £180,000, your LTV is 90%.

Lenders will set a maximum LTV for each deal they offer - for example, a particular interest rate may only be available to those with an LTV of 75% or below. In general, the lower your LTV (ie the more money you're putting in yourself), the lower the mortgage rate, and the cheaper the overall deal.

It's still possible to get a mortgage with a smaller deposit. However, virtually no lenders offer anything more than a 95% LTV mortgage, meaning you need at least a 5% deposit to buy. 

LTV calculator: work our your loan-to-value 


Affording your mortgage repayments into the future 

A mortgage is a long-term investment, so you need to think about expenses you may have in the future. 

Lenders will commonly ask about any upcoming life events that could have a significant impact on your finances, such as having children or starting a business. 

Our mortgage affordability calculator lets you factor in the cost of these future expenses to see what impact they are likely to have.

How do interest rates affect how much you can borrow?

Interest rates will play a deciding role in how much you can borrow. Lenders won't just look at what you can afford to repay at current interest rates - they'll also 'stress test' to see what you could pay if rates increased.

In general, lenders will check to see if you could withstand at least a three percentage point rise in rates. 

If you have a fixed rate, future interest rate changes are unlikely to affect you. However, if you have variable-rate mortgage, the interest rate on your monthly repayments will fluctuate throughout the length of your term. 

Our mortgage repayment calculator shows how a 3% rate rise would affect your monthly repayments to help you work out what you can afford.

Want impartial advice?

While there are some general rules that help you work out roughly how much mortgage you might be able to borrow, the exact amount will always be unique to you and your personal circumstances. 

For an accurate understanding of how much you can borrow, talk to an impartial expert by calling Which? Mortgage Advisers on 0808 252 7987.


Correct as of date of publication.

  • Last updated: January 2018
  • Updated by: Ele Clark

Your home may be repossessed if you do not keep up repayments on your mortgage.

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