Property & Mortgages
Mortgage Affordability Calculator
Estimate how much you could borrow based on your income and deposit, across conservative, typical, and maximum lending multiples.
Your details
Rate and term are used for estimated monthly payments only
Your results
£45,000/year Income, Borrowing Estimate
Estimated borrowing (typical 4.5×)
£202,500
Property price affordable
£242,500
- Deposit
- £40,000
- Loan to value (LTV)
- 84%
- Est. monthly payment
- £1,126
Breakdown
Borrowing estimates · £45,000/yr income
Conservative (4×)
£180,000
Property price
£220,000
Typical (4.5×)
£202,500
Property price
£242,500
Maximum (5×)
£225,000
Property price
£265,000
Income multiple estimates only. Actual lender decisions depend on credit history, monthly outgoings, existing debts, and individual affordability assessments.
Affordability Guide
How lenders assess affordability
Mortgage affordability is not just about your income. Since the Mortgage Market Review (MMR) in 2014, UK lenders are required to carry out detailed affordability assessments that go well beyond a simple income multiple.
The income multiple rule of thumb
Most UK lenders will lend between 4 and 4.5 times your gross annual income. Some will go to 5 times, particularly for higher earners (typically above £60,000–£75,000) or professionals in regulated fields. On a joint application, most lenders combine the two incomes before applying the multiple. These multiples are a starting point, not a guarantee Your actual offer may be higher or lower depending on your full financial picture.
Affordability stress tests
Lenders do not just check you can afford payments today. They stress test whether you could still afford them if interest rates rose by around 3% above your initial rate. This means a borrower qualifying at 4.5% must demonstrate they could manage payments at roughly 7.5%. If your income is tight relative to the loan size, the stress test can be the binding constraint, reducing your actual offer below the headline income multiple.
Monthly outgoings and existing debts
Lenders deduct your regular monthly commitments from your disposable income before assessing affordability. Car finance, credit card minimum payments, student loans, subscriptions, and childcare costs all reduce what a lender considers available for mortgage payments. Clearing debts before applying (or reducing credit card limits) can meaningfully improve your affordability position.
How your deposit helps
A larger deposit lowers your LTV, which gives you access to better interest rates and makes you a lower-risk borrower. At 75% LTV or below, most mainstream lenders offer their most competitive products. At 90% or 95% LTV, the choice of lenders narrows and rates are higher, which increases your monthly payment and may reduce the loan size you can sustain. Saving a larger deposit, even by delaying a purchase slightly, can have a significant effect on the total cost of your mortgage.
Frequently asked questions
Related guides
Sources & methodology
Built and maintained by Tim, a personal finance enthusiast (not a financial adviser). Last reviewed April 2026. Rates and thresholds come from official UK government publications.
- FCA: Mortgage conduct of business · Affordability rules and lending standards
- Bank of England: Base rate · Current and historical base rates
- HMRC: Income Tax rates and allowances · Official rates, bands and thresholds
- GOV.UK: National Insurance rates · Employee and employer NI rates
- Scottish Government: Income Tax · Scottish income tax rates and bands
Figures are estimates only. This is not financial or tax advice. For help with your specific situation, speak to HMRC or a qualified adviser.