UK Mortgage Affordability Calculator
Use this mortgage affordability calculator to estimate how much you might be able to borrow and what property price that could mean. Enter your income, deposit and monthly commitments, then adjust the assumptions to see how the estimate changes.
Advanced assumptions (optional)
This calculator gives a rough estimate of how much you might be able to borrow, using two common limits.
- Income multiple: your household annual income times the multiple you enter.
- Payment based: works backwards from a maximum monthly payment (based on your income and commitments) to an estimated loan size.
The “maximum loan” shown is the lower of those two limits. The property price estimate is maximum loan plus your deposit.
This is not lender advice and does not include credit checks, stress tests, fees, or rate changes.
This is a guide only. Different lenders have different affordability models and may offer more or less than this estimate.
If you need a figure you can rely on, speak to a qualified mortgage adviser or check directly with lenders.
This affordability calculator gives a planning estimate based on two common ways borrowing can be limited: an income-multiple cap and a payment-based cap.
- Income multiple cap: (your household gross income) × (the multiple you choose).
- Payment-based cap: estimates a maximum affordable monthly mortgage payment, then works backwards to a loan size using the rate and term you enter.
- Result: your “max loan” is the lower of those two caps, and “max property price” adds your deposit.
Because lenders differ, the goal here is to help you stress-test scenarios and understand which constraint is doing the limiting.
Last verified: 05/03/2026. Lenders’ affordability rules vary; this page uses user-entered assumptions rather than a fixed lender policy table.
Inputs that act like “thresholds” here are choices, not official limits:
- Income multiple: a simple way to model an income cap. Try a range to see sensitivity.
- Max payment share: models a payment-based limit (for example, “no more than X% of gross income”).
- Interest rate: acts like a stress assumption. Higher rates reduce the loan size under the payment-based cap.
If you’re comparing scenarios, change one input at a time (rate, term, deposit, commitments) to see what moves the result most.
These worked examples are generated from the same calculator logic as the UI. Values are rounded for display.
Example 1 — Income multiple binds
- Income: £60,000; multiple: 4.5 → income cap £270,000
- Deposit: £30,000 → max property price £300,000
- Illustrative repayment at 5.00% over 25y: £1,578.39/month
- LTV in this scenario: 90%
Example 2 — Two incomes with commitments
- Income: £40,000 + £30,000; commitments: £1,000/month
- Multiple: 4 → income cap £280,000
- Deposit: £20,000 → max property price £300,000
- Illustrative repayment at 6.00% over 30y: £1,678.74/month
Example 3 — Payment-based cap binds
- Income: £100,000; commitments: £2,500/month
- Max payment share: 30%; rate: 6.00%; term: 25y
- Payment-based max loan ≈ £271,612.01 (this becomes the max loan)
- With a £50,000 deposit → max property price ≈ £321,612.01
- Illustrative repayment: £1,750.00/month
- Net vs gross pay: the calculator uses gross inputs; real affordability is often driven by net take-home pay and household outgoings.
- Variable income: bonuses, commission, overtime, and self-employed income can be treated differently by different lenders.
- Commitments: childcare, student loans, credit cards, and car finance can materially reduce affordability.
- Interest-rate stress: the rate input changes payment-based borrowing a lot—test higher-rate scenarios.
- Deposit source checks: this tool doesn’t check gifted deposit rules or proof-of-funds requirements.
- Figures are before tax (gross).
- This is a simplified estimate - lenders use their own affordability models and stress tests.
- The interest rate is assumed to stay the same for the full term.
- Monthly commitments reduce the income available for mortgage payments.
- It does not include lender fees, broker fees, valuation fees, legal costs, insurance, or taxes.
Income multiple cap: household annual income multiplied by your chosen multiple.
Payment based cap: estimates a maximum monthly payment from your income and commitments, then works backwards to a loan size using the interest rate and term.
Maximum loan is the lower of those two caps.
Property price estimate is maximum loan plus your deposit.
- Try a repayment scenario once you have a target property price and deposit.
- Work backwards from a deposit if you’re still budgeting upfront cash.
- Read: AIP explained to understand what lenders check.
- Read: How much deposit do I need?
- Glossary: AIP, LTV, APRC.