Work out what you could afford once your fix ends
This calculator takes your income, outgoings and the details of your current mortgage to estimate what you might be able to afford when you remortgage. It gives you a working figure to start from, not a lender's decision, because affordability rules vary by lender and change over time.
Affordability calculator: work out what you could realistically borrow
The affordability calculator works out roughly how much you could borrow, based on your income and outgoings, and sets that against what you currently owe. This guide is for homeowners coming up to the end of a fixed-rate deal who want a starting figure before they talk to anyone. It can give you a wrong answer if your income or outgoings change, or if a lender applies stricter rules than the ones built into this tool.
-
Enter your income and outgoings
Enter your income and regular outgoings, the two figures that decide how much borrowing you could support each month.
-
Add your mortgage details
Enter your outstanding balance and remaining term so the calculator can compare what you owe against what you could borrow.
-
Read what the result tells you
Look at the figure against your current balance and understand that it's an estimate based on your inputs, not a lender's own affordability check.
Mortgage Affordability Calculator
Estimate how much you could borrow for a mortgage based on your household income, regular outgoings, and typical lender stress-test rates. This gives you an indicative borrowing range before you speak to a lender or broker.
Your Indicative Results
How this calculator works
This tool produces an indicative borrowing estimate using two industry-standard checks and taking the lower of the two:
- Income multiple: Your total assessed annual income multiplied by the income-multiple cap (typically 4.5×).
- Affordability & stress test: Your monthly disposable income (income minus outgoings, dependant costs and credit commitments) is used to work out the largest loan whose repayment — calculated at the lender's higher stress-test rate — you could still afford.
Lenders "stress" your ability to pay at a rate higher than the initial pay rate to ensure you could cope if interest rates rose. We apply a repayment (capital & interest) formula over your chosen term at that stress rate.
Important: This is a guide only and not a mortgage offer or financial advice. Actual lending decisions depend on credit history, individual lender criteria, and a full assessment of your circumstances. Always speak to a qualified mortgage adviser.
Check what you could afford, then plan your next move
This calculator gives you an estimate of what you might be able to borrow, based on the figures you enter yourself. It's built for homeowners thinking about a remortgage, and it can only work with the numbers you give it. Treat the result as a starting point for a conversation with a lender or broker, because it can give you a wrong answer if your circumstances change or your inputs are off.
No sign-up · Free to use · Works on any device
Popular Tools
Early Repayment Charge Estimator
An interactive Early Repayment Charge Estimator, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Early Repayment Charge Estimator | ToolsLTV & Equity Position Calculator
An interactive LTV & Equity Position Calculator, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
LTV & Equity Position Calculator | Tools
Mortgage Overpayment Calculator
An interactive Mortgage Overpayment Calculator, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Tools / Mortgage Overpayment Calculator
Variable Rate Stress Test
An interactive Variable Rate Stress Test, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Tools / Variable Rate Stress TestFee analyser
An interactive Fee analyser, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Tools / Fee analyserAffordability calculator
An interactive Affordability calculator, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Tools / Affordability calculator