Mortgage Affordability Calculator

What Is a Mortgage Affordability Calculator?

A mortgage affordability calculator provides an estimate of how much you may potentially be able to borrow for a property purchase. It uses information such as gross annual income, available deposit, an illustrative income multiple, interest rate and mortgage term to produce an estimated borrowing amount and property price.

The calculator can be useful when planning a home purchase, comparing different mortgage assumptions or working out how different deposits and mortgage terms could affect monthly payments. It is intended as a planning tool rather than a replacement for a lender's affordability assessment.

Why Use Mortgage Affordability Calculator?

Understanding potential borrowing before looking at properties can help you establish a realistic starting point and compare different mortgage scenarios.

How to Use Mortgage Affordability Calculator

Enter the financial assumptions you want to use for your illustrative mortgage calculation, then calculate your estimated borrowing capacity and property price.

1. Enter your gross annual income — Enter your annual income before tax and other deductions.
2. Enter your deposit — Enter the amount you have available to put towards the property purchase.
3. Choose an income multiple — Enter an illustrative borrowing multiple to estimate potential mortgage borrowing.
4. Enter the interest rate and term — Enter an assumed annual interest rate and mortgage term, then select Calculate Affordability.

How Much Mortgage Can I Afford?

How much mortgage you can afford depends on more than your annual income. Mortgage lenders may consider your income, regular expenditure, existing borrowing, credit history, employment circumstances and other financial commitments when assessing an application. The amount a lender is willing to offer can therefore be different from a simple income multiple calculation.

This mortgage affordability calculator uses an adjustable income multiple to provide a simple starting estimate. For example, an income of £50,000 multiplied by 4.5 produces an illustrative mortgage borrowing figure of £225,000. Adding a £50,000 deposit would give an estimated property price of £275,000 before considering other purchasing costs.

How Income Multiples Affect Mortgage Affordability

An income multiple is a simple way of relating gross annual income to an illustrative mortgage amount. Increasing the multiple increases the estimated borrowing amount, while reducing it produces a more conservative estimate.

Income multiples should not be treated as guaranteed mortgage offers. Different lenders use different affordability models, and some applications may be assessed using detailed income and expenditure information rather than relying on a simple multiple alone.

How Deposit and Interest Rate Affect Affordability

A larger deposit can increase the total property price you could potentially consider because less of the purchase price needs to be financed through the mortgage. It also reduces the mortgage amount relative to the property's value, which reduces the loan-to-value ratio.

The interest rate and mortgage term affect the monthly payment required to repay a given mortgage. A higher interest rate generally increases the monthly payment, while extending the mortgage term can reduce the monthly payment but may increase the total interest paid over the life of the mortgage.

Mortgage Affordability Calculator Information

The borrowing estimate produced by this calculator is based on the gross annual income multiplied by the income multiple entered. The estimated property price is then calculated by adding the deposit to that borrowing amount. The monthly payment is calculated using a standard capital-and-interest repayment mortgage formula.

The calculator does not account for individual lender affordability rules, household expenditure, existing debts, credit history, employment type, age, dependants, taxes, insurance, mortgage fees or other purchasing costs. It should therefore be used as an illustrative planning tool rather than as an indication that a mortgage application will be accepted.

Actual mortgage rates and borrowing limits vary between lenders and products. Before committing to a property purchase, consider obtaining an affordability assessment or mortgage decision from an appropriate lender or qualified professional.

Frequently Asked Questions