What this calculator does
This free UK mortgage affordability calculator estimates how much you may be able to borrow based on your annual income and a chosen income multiple. Select 4x, 4.5x or 5x income, enter your gross annual salary (or combined income for a joint application), and the calculator returns a borrowing estimate.
The income multiple approach is how most UK lenders set an initial borrowing limit. It is a starting point only — actual mortgage offers also depend on deposit size, debts, credit history, monthly outgoings, and the lender's internal affordability model. Use this estimate as a planning figure, not as a guaranteed borrowing amount.
How lenders assess mortgage affordability
UK mortgage lenders use two layers of assessment:
1. Income multiple cap: The FCA's mortgage affordability rules limit lending above 4.5x income to no more than 15% of new residential mortgages. In practice, most lenders offer 4x–4.5x income for standard applications. Some specialist lenders or those targeting higher earners may stretch to 5x–5.5x with strong supporting criteria.
2. Affordability assessment: Beyond the income multiple, lenders model the actual monthly payment against your disposable income — income minus committed expenditure (debts, bills, childcare, pension contributions). They also stress test the repayment at a higher rate to check resilience if rates rise.
The lower of the income multiple limit and the affordability model determines what a lender will offer. It is common for borrowers with high incomes but significant debts to be offered less than the headline income multiple suggests.
Example calculations
| Annual income | At 4x | At 4.5x | At 5x |
|---|---|---|---|
| £30,000 | £120,000 | £135,000 | £150,000 |
| £45,000 | £180,000 | £202,500 | £225,000 |
| £60,000 | £240,000 | £270,000 | £300,000 |
| £80,000 | £320,000 | £360,000 | £400,000 |
| £50,000 + £40,000 (joint) | £360,000 | £405,000 | £450,000 |
Once you have a borrowing estimate, add your deposit to get a target property price, then use our mortgage calculator to check whether the monthly repayment is comfortable at current rates.
When to use this calculator
- Setting your property search budget — add your estimated borrowing to your deposit to get a realistic maximum property price before you start viewing.
- Comparing single vs joint applications — check how much extra borrowing a second income adds on a joint mortgage.
- Planning ahead — see how much more you could borrow with a salary increase, a promotion, or a larger deposit.
- Understanding the gap between what you want and what you can borrow — if properties in your target area cost more than the estimate, the calculator shows how much income or deposit growth you would need.
Common mistakes
Forgetting existing debts reduce borrowing capacity
A car loan, personal loan or significant credit card balance reduces disposable income and can cut the mortgage offer well below the income multiple estimate. A lender seeing £500/month in existing debt commitments may reduce the mortgage offer by £50,000–£80,000 depending on rates.
Using net salary instead of gross income
Income multiples are applied to gross (before tax and NI) annual income. Enter your gross salary, not take-home pay. For self-employed applicants, lenders typically use net profit or the combination of salary and dividends — not gross turnover.
Assuming 5x income is widely available
Lending above 4.5x income is restricted by regulation to a small proportion of mortgage lending. Some lenders offer it only to higher-income borrowers (often above £75,000 per year) or for specific professional mortgages (doctors, solicitors, accountants). Most first-time buyers should plan around 4–4.5x income.
Not stress-testing the monthly repayment
Borrowing capacity is only one side of affordability. The monthly repayment at today's rate may be comfortable, but at a 2–3% higher rate it may not be. Use our mortgage calculator with a stress-test rate before committing to a loan amount.
Frequently asked questions
How many times my salary can I borrow?
Most UK lenders offer 4x–4.5x gross annual income. The FCA limits lending above 4.5x to no more than 15% of new lending. Some lenders stretch to 5x–5.5x for high earners or professionals. Joint mortgages use combined income.
What income counts towards a mortgage application?
Lenders count employed gross salary as the primary figure. Many also accept guaranteed overtime, averaged commission and bonus, second job income, and some benefits. Self-employed applicants typically need 2–3 years of accounts, using net profit or salary and dividends.
Do debts reduce how much I can borrow?
Yes. Car finance, personal loans and credit card balances reduce disposable income. Lenders model your monthly commitments against income, so high existing debt levels can significantly reduce the mortgage offer below what the income multiple alone suggests.
What is a mortgage stress test?
Lenders check whether you could still afford the mortgage if rates rose significantly. Most lenders apply an internal stress test at 6–8%, even if today's rate is lower. If the stressed repayment exceeds affordability limits, the lender may reduce the loan amount.
Does a bigger deposit mean I can borrow more?
A larger deposit reduces the LTV ratio and can unlock lower rates, which improves affordability. It does not directly increase the income multiple, but lower rates make the monthly payment more manageable, and lenders may be more flexible with a lower LTV risk profile.
Should I get a mortgage in principle before viewing properties?
A Mortgage in Principle (MIP), also called an Agreement in Principle (AIP) or Decision in Principle (DIP), is a conditional indication from a lender of how much they may lend, based on a soft credit check. It is useful for demonstrating to estate agents and vendors that you are a credible buyer. See our guide on mortgage agreements in principle.
Related calculators
Related guides
How much mortgage can I afford?
How lenders calculate affordability and what limits borrowing
Complete first-time buyer guide UK
From saving a deposit to getting the keys
Mortgage agreement in principle explained
What a MIP is, how to get one, and what it means for your offer
What credit score do you need for a mortgage?
How credit history affects rates and approval chances
Important information
This calculator is for general information and planning purposes only. Results are estimates based on income multiples and do not represent a mortgage offer, commitment to lend, or assessment of your individual creditworthiness.
Actual mortgage offers depend on your credit history, existing financial commitments, deposit size, employment status, the lender's specific affordability model, and their internal stress testing. A qualified, FCA-regulated mortgage broker or adviser can provide a realistic borrowing assessment based on your full financial circumstances.
This is not mortgage or financial advice. Read our full Disclaimer.
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✓ Editorially reviewed — all Poqet guides are checked for factual accuracy before publication and updated when UK rates or legislation change. Editorial Policy