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Mortgage Affordability Calculator

Estimate how much you could borrow based on income, deposit and commitments — including the interest-rate stress test lenders apply.

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Car finance, personal loans, minimum card payments, childcare.

Lender assumptions — 4.5× income, stress-tested at 7.5%

4.5× is the norm; 5–5.5× for some higher earners.

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Many lenders test around 3 points above the rate.

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For the mortgage and other debts, at the stress rate.

Affects take-home pay.

£192,643

Estimated maximum mortgage · buy up to £222,643 with your £30,000 deposit (87% loan-to-value)

Income multiple: 4.5× £45,000£202,500
Affordability: 45% of £2,993/month take-home at 7.5%£192,643
Monthly payment at your rate£976
Monthly payment if rates hit 7.5%£1,347

The lower of the two limits applies — here, the affordability stress test.

90% LTV band

Lenders price by loan-to-value. You're in the 90% band; a deposit of £33,396 on the same price would move you into the 85% band, usually at a lower rate.

An estimate, not an offer

Every lender has its own affordability model and will look at your credit file, spending, and the property itself. A mortgage broker can tell you which lenders go above 4.5× for your circumstances. Remember stamp duty, legal fees and a survey on top of the deposit.

Loan-to-income context: Bank of England — high loan-to-income lending.

How to use

Enter your income before tax, your deposit and any monthly debt payments. If you're buying with someone, tick the box and add their income. The default lender assumptions — 4.5× income, a stress test at 7.5%, and housing costs no more than 45% of take-home pay — are typical; open Lender assumptions to change them.

The two limits lenders apply

  1. Income multiple. Your gross income times a multiple, usually 4.5. Existing commitments reduce the income the multiple is applied to.
  2. Affordability. Whether the monthly payment at a stressed interest rate, plus your existing commitments, fits within a share of your take-home pay.

You can borrow the lower of the two. For most people on typical rates the income multiple binds; when rates are high or take-home pay is squeezed, the stress test does.

Worked example

A couple earning £45,000 and £35,000 (£80,000 together) take home about £5,387 a month. At 4.5× income they could borrow £360,000. At a 7.5% stress rate over 30 years, 45% of their take-home supports a loan of £346,670. The lower figure is £346,670, so with a £30,000 deposit they could look at homes up to about £376,670 — a 92% loan-to-value mortgage costing about £1,757 a month at 4.5%.

Budget for the rest

The deposit isn't the only cash you need. Work out the stamp duty on the price you're aiming for, and allow for legal fees, a survey and moving costs. Once you've found a property, the mortgage calculator shows the full repayment schedule, and the council tax calculator the running cost you'll pay on top.

Frequently asked questions

How much can I borrow for a mortgage?

Most UK lenders cap lending at around 4.5 times your gross annual income — £360,000 on a joint £80,000 — and then check you could afford the payments if interest rates rose. The lower of the two is your limit. Some lenders go to 5 or 5.5 times for higher earners or certain professions.

Why 4.5 times income?

The Bank of England limits mortgages at or above 4.5 times income to 15% of new lending across the market, so most lenders keep most customers under it. A 2026 consultation by the PRA and FCA gives individual lenders more flexibility above 4.5×, but the aggregate limit stays.

What is a mortgage stress test?

Lenders check whether you could keep paying if your rate went up — typically by testing at a rate a few points above the one you're offered. There's no single regulatory stress rate any more; each lender sets its own. The calculator lets you set it, and shows the payment at that rate.

Do car finance and credit cards affect how much I can borrow?

Yes, directly. In the example on this page, a £350 monthly car finance payment cuts the maximum mortgage from £346,670 to £296,614. Clearing a small loan before applying can raise your limit by far more than the balance.

What deposit do I need?

Usually at least 5% of the price, but rates improve at each loan-to-value step — 90%, 85%, 80%, 75% and 60%. The calculator shows your LTV band and the deposit that would move you into the next one.

Is this a mortgage offer?

No. It's an estimate from the typical rules. A lender will look at your credit file, your spending, your job and the property itself. A mortgage broker can tell you which lenders fit your situation.

Is anything I enter sent anywhere?

No. The calculation runs in your browser.

Not financial advice

This tool provides estimates for general information only and is not financial, tax, or legal advice. Figures may not reflect the latest rules — verify with HMRC, Scottish Government, MHCLG, Revenue Scotland and Welsh Revenue Authority before making decisions.
  • Everything you type or open here is processed by your own browser. It is not sent to us and we could not read it if we wanted to.
  • Formatted for United Kingdom (en-GB), in GBP.

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