Mortgage Stress Test Calculator 2025
Calculate if you can afford your mortgage payments if interest rates rise with our professional UK mortgage stress test calculator. This advanced tool helps you prepare for potential rate changes and assess your financial resilience by testing various interest rate scenarios. Updated for October 2025 UK market conditions. Whether you're considering a new mortgage, remortgaging, or planning for economic uncertainty, our stress test calculator provides detailed affordability analysis showing payment increases, affordability ratios, and remaining income after expenses. Use alongside our affordability calculator to understand your borrowing capacity and our repayment calculator to explore different mortgage terms and rates for optimal financial planning and risk management.
Test Your Mortgage Affordability
Your Stress Test Results
Current Monthly Payment
£0
New Monthly Payment
£0
Monthly Increase
£0
Affordability Analysis
Current Affordability
0%
of monthly income
New Affordability
0%
of monthly income
Remaining Income
£0
after mortgage and expenses
Understanding Mortgage Stress Testing
Professional stress testing methodology used by UK lenders and financial advisors:
- Payment calculations: Uses standard PMT formula with current and stressed interest rates to calculate monthly payments accurately
- Affordability ratios: Calculates mortgage payments as percentage of gross monthly income - industry standard for risk assessment
- Remaining income analysis: Determines disposable income after mortgage payments and essential expenses for financial buffer assessment
- 35% affordability rule: UK lenders typically require mortgage payments below 35% of gross income, though this varies by lender and circumstances
- Stress test standards: Minimum 2-3% rate increase recommended for realistic financial resilience testing
- Risk indicators: High affordability ratios (>35%) and low remaining income (<£500) indicate potential financial stress
Professional advice: Use our overpayment calculator to explore strategies for reducing mortgage risk through additional payments.
Frequently Asked Questions
Essential information about mortgage stress testing in the UK
What is a mortgage stress test?
A mortgage stress test is a calculation that helps you determine if you can afford your mortgage payments if interest rates rise. It's a way to prepare for potential rate changes and ensure you can maintain your mortgage payments even in less favorable economic conditions.
How much should I stress test my mortgage?
It's recommended to stress test your mortgage for at least a 2-3% increase in interest rates. This helps ensure you can handle potential rate rises. Some experts suggest testing for even higher increases to be more conservative in your planning.
What is a good affordability ratio?
Lenders typically look for mortgage payments to be no more than 35% of your gross monthly income. However, this can vary depending on your overall financial situation, other debts, and the lender's specific criteria.