House Affordability Calculator UK

Run a UK house purchase through the 50/30/20 rule and stress test the mortgage against ±10pp interest rate moves. Set against 100 years of Bank of England base rate history so you can see how common today's rate actually is.

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Your numbers

House price

Deposit

LTV: 90.0%

Interest rate (current quote)

The headline fixed-rate quote. The stress test below shows what happens if rates move ±10 percentage points.

Term

years

Annual household gross income

Combined gross salary for the household. Used to estimate take-home pay and the share of net income the mortgage will consume.

Tax region

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Mortgage size

£270,000

£30,000 deposit

Monthly payment

£1,501

39.7% of net income (Risky)

Recommended buffer

£673/mo

Extra cushion to survive a +4pp rate shock when your fix ends

Against the 50/30/20 budgeting rule

The 50/30/20 rule allocates 50% of net pay to needs (housing, bills, food, transport), 30% to wants, 20% to savings. Housing alone should not consume the whole needs bucket - standard UK guidance is below 28% comfortable, 28-35% stretched, above 35% risky.

Mortgage

£1,501/mo

28% line

£1,058/mo

35% line

£1,323/mo

50% needs

£1,890/mo

Risky: Mortgage exceeds 35% of net income at the entered rate. Either increase the deposit, lower the price, or genuinely re-examine whether this purchase is sustainable.

Stress test: interest rate moves ±10pp

Your initial fixed-rate term ends in 2-5 years. After that, the variable rate you revert to could be materially higher or lower than today's quote.

Rate	Monthly	% of net	Band
-10pp (0.00%)	£900	23.8%	Comfortable
-8pp (0.00%)	£900	23.8%	Comfortable
-6pp (0.00%)	£900	23.8%	Comfortable
-4pp (0.50%)	£958	25.3%	Comfortable
-2pp (2.50%)	£1,211	32.0%	Stretched
Entered (4.50%)	£1,501	39.7%	Risky
+2pp (6.50%)	£1,823	48.2%	Risky
+4pp (8.50%)	£2,174	57.5%	Risky
+6pp (10.50%)	£2,549	67.4%	Risky
+8pp (12.50%)	£2,944	77.9%	Risky
+10pp (14.50%)	£3,354	88.7%	Risky

Bank of England base rate, last 100 years

UK mortgage rates have historically tracked the Bank Rate (with a few percentage points on top). The 1970s-80s peaks reached 17%; the 2009-2021 floor sat near zero. Source: Bank of England.

How often UK base rates have been at each level

Years out of the 101-year sample (1925-2025).

Rate band	Years	% of time
Under 2%	13	12.9%
2-4%	26	25.7%
4-6%	25	24.8%
6-8%	16	15.8%
8-10%	6	5.9%
10-15%	13	12.9%
15% or higher	2	2.0%

Build a buffer before you stretch on price

Your fixed-rate term ends in 2-5 years. The variable rate you revert to is set when the fix ends, not now.
Over the last 100 years, UK base rates have been above 6% for 37% of the sample and above 10% for 15%. The 2009-2021 near-zero floor was an outlier, not the norm.
Aim for a 3-6 month emergency fund before completion, plus a separate sinking fund that covers the £673/month difference between today's payment and a +4pp shock. Six months at that buffer is roughly £4,040 set aside.
The cheapest place to absorb a rate rise is a lower house price today, not a bigger salary in two years.

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The complete guide

House Affordability Calculator UK: How Much Can You Borrow?

Work out how much house you can afford in the UK. Lender income multiples, the 5%+1% stress test, deposit and LTV bands, plus the full cost of buying.

Lenders will quote you one number. Your bank account will quote you a smaller one. The job of an honest affordability check is to find the gap between those two answers before you sign a 25-year contract for the larger one.

Plug your numbers into our house affordability calculator to see the mortgage size, the monthly payment, and what happens when the Bank Rate moves. The rest of this guide explains what the inputs actually mean in UK terms and why the lender's ceiling is almost never the right place to buy.

What "affordable" means to a UK lender
How to use the calculator
Worked example: a couple on £80k buying London vs Yorkshire
The lender stress test, in plain English
The cost of owning, not just buying

What "affordable" means to a UK lender

A UK lender's idea of "affordable" is a formula, not a judgement. The starting point is an income multiple: roughly 4 to 4.5 times your gross household income. A couple earning £80,000 between them will be offered around £320,000 to £360,000.

Some lenders push higher. First-time buyer schemes like Skipton's 100% Track Record mortgage, Nationwide's Helping Hand, and a handful of professional mortgages will stretch to 5x or even 5.5x income, but usually only above a minimum salary floor (typical published thresholds sit around £35,000 single or £55,000 joint, though each lender sets its own) and only with a clean credit file. Anything above 5x is the exception, not the rule.

Whatever multiple you qualify for is then reduced by your existing commitments. Credit card balances, personal loans, car finance, student loan repayments, and dependant children all chip away at the headline number. A couple with £400/month in childcare and £300/month in car finance can lose £60,000 to £80,000 of borrowing power before the income multiple is even applied.

Finally the lender runs an affordability assessment built on your bank statements. They want to see at least three months of inflows and outflows that look like the budget you've put on the application form. Big regular gambling debits, sudden gifts that look like undeclared loans, or anything that looks like a payday lender will get flagged.

The point worth holding onto: the lender's job is to lend you the maximum amount their model says you can pay without defaulting. Defaulting is not the same as living comfortably. The gap between those two definitions is where most "house-poor" households are made.

How to use the calculator

The house affordability calculator takes five inputs and produces three answers you actually need.

Inputs:

House price. The asking price, or the offer you're considering. Use the realistic number, not the wishful one.
Deposit. Cash you can put down today, including any LISA bonus and gifted deposits. The calculator shows your loan-to-value (LTV) as you type so you can see which rate band you'll land in.
Interest rate. Use the headline rate from a real mortgage comparison site, not the Bank Rate. In mid-2026, broadly-quoted 75% LTV two-year fixes have been sitting in the 4-5% range; always check a live comparison site for the rate you would actually be offered.
Term. Default to 25 years for a clean comparison. The calculator lets you stretch to 40, but a longer term means more interest paid, not a more affordable house.
Annual household gross income. Combined gross salary. The calculator runs this through the UK tax bands to estimate your net monthly take-home, then benchmarks the mortgage against that net figure rather than your gross.

Outputs:

The summary cards show the mortgage size, the monthly payment, and the recommended buffer you'd want sitting in a savings pot to absorb a 4-percentage-point rate shock when your fix ends. The 50/30/20 panel tells you whether the payment is comfortable (under 28% of net), stretched (28-35%), or risky (above 35%). The stress test below shows what the same mortgage costs if rates move plus or minus 10 percentage points, which sounds extreme until you look at the 100-year Bank Rate chart underneath it.

For a deeper run at the borrowing side, pair this tool with our mortgage calculator for the amortisation schedule, and the LTV band overpayment calculator to see whether overpaying to drop an LTV band is worth the cash.

Worked example: a couple on £80k buying London vs Yorkshire

Same household, two postcodes, two completely different answers.

The household. Partner A earns £45,000, Partner B earns £35,000. Combined gross is £80,000, net take-home roughly £5,150/month after PAYE and NI. They have £40,000 in deposit and no debts.

Yorkshire scenario. They find a three-bed terrace in Leeds at £220,000. Mortgage of £180,000 at 4.5% over 25 years gives a monthly payment of about £1,000. That's 19% of net income: comfortable. LTV of 82%, which sits in the 85% rate band, so they get a decent rate. Stamp Duty Land Tax for first-time buyers is zero up to £300,000, so there's no SDLT bill. Including fees and moving costs they need about £6,000 on top of the deposit. The lender's ceiling is around £360,000, so they're buying at roughly 60% of their borrowing capacity.

London scenario. Same couple, same £40,000 deposit, looking at a one-bed flat in Zone 3 at £420,000. Mortgage of £380,000 at 4.5% over 25 years is a monthly payment of about £2,113. That's 41% of net income: risky. LTV of 90.5%, which pushes them into the worst rate band; the actual rate would be higher than 4.5%, making the bill worse. SDLT for first-time buyers is zero up to £300,000, then 5% on the slice to £450,000, so they pay £6,000 in stamp duty on top. Service charges on a one-bed flat add another £150-£250/month. The lender will still sign this off, because £380,000 is roughly 4.75x income and the stress test passes. The household will not.

The Yorkshire couple banks roughly £1,100/month they would otherwise have paid in mortgage. Invested at a hypothetical 6% annual return over 25 years, that compounds into a pot somewhere north of £750,000 - a worked illustration, not a forecast. Real returns vary, can be negative in any year, and past performance is not a guide to future results. The London couple gets the postcode. The difference, in this scenario, is the entire retirement.

The lender stress test, in plain English

Every UK residential mortgage runs through an affordability stress test required by the Bank of England's Financial Policy Committee. The mechanic is simpler than it sounds.

The lender takes a stressed rate built from the initial fixed rate (or the reversion rate on a tracker) and applies a buffer on top, typically a margin over the reversion or standard variable rate set by the lender under PRA guidance. They then ask: would the borrower still be able to afford this payment under that hypothetical higher rate? If the answer is no, the loan is reduced or refused.

In practice that means a 4.5% headline rate gets tested at roughly 5.5%, and on some lender's models 7-8%. On a £300,000 mortgage over 25 years, that's the difference between £1,668/month at 4.5% and £2,042/month at 7%. If the household couldn't fit £2,042/month into their budget alongside their other commitments, the lender trims the offer.

This matters for two reasons. First, the stress test is the reason "I earn £80k so I can borrow £400k" doesn't always pan out. A high earner with significant childcare costs and a car finance bill can have their offer cut to £320k or less. Second, the stress test is also the lender's honest warning to you. The rate they're testing at is the rate that has historically applied to UK mortgages for the majority of the last hundred years. Today's sub-5% rates are the unusual ones, not the norm. Building a household budget that only works at 4.5% is building on sand.

The cost of owning, not just buying

The deposit is the headline number every buyer fixates on. It's also the number that hides most of the actual cost.

Stamp Duty Land Tax (England and Northern Ireland, 2026-27 - check gov.uk for the current bands before you offer):

0% up to £125,000
2% on the slice £125,001 to £250,000
5% on the slice £250,001 to £925,000
10% on the slice £925,001 to £1.5m
12% above £1.5m

First-time buyers pay 0% up to £300,000 and 5% on the slice to £500,000. Above £500,000 first-time buyer relief vanishes entirely and the standard bands apply on the full price. Run the bill in our stamp duty calculator before you offer.

The rest of the ambush:

Legal and conveyancing fees: £1,200 to £2,500 including searches, Land Registry fees, and AML checks.
Survey: £400 for a Level 2 HomeBuyer report, up to £1,500 for a Level 3 building survey on anything older than 1960 or with visible quirks.
Mortgage product fee: £0 to £999, usually £995. Compare the true cost against a fee-free deal at a slightly higher rate.
Buildings and contents insurance: £200 to £600/year, mandatory from completion day.
Removals and immediate fitting-out: £500 to £2,000 for the move plus white goods, curtains, and whatever the survey didn't catch.

That's roughly 3 to 5% of the property price in upfront costs on top of the deposit. Then come the ongoing bills the rental market hid from you:

Council tax runs £1,500 to £2,500/year for a typical Band D property and is set per local authority.
Service charges and ground rent on leasehold flats can be £1,200 to £3,000/year and rise faster than wages.
Maintenance sinking fund. A standard rule is 1% of property value per year set aside for repairs and replacements. On a £300k house that's £3,000/year you should be saving even in years when nothing breaks.

If you want to weigh up the cost of owning against renting and investing the difference, our should I overpay my mortgage breakdown covers the trade-off once you're in. For mapping which UK regions are actually affordable on your income, the UK mortgage affordability map shows the picture by postcode.

Frequently asked questions

How much can I borrow for a UK mortgage?

Most UK lenders cap mortgage borrowing at around 4.5 times your annual household income. Some lenders will stretch to 5.5x for higher earners (typically over £75,000) or for certain professions. Joint applications combine both incomes. The headline multiple is then reduced by any credit commitments, childcare costs, and a stress test that checks you could still pay if rates rose to roughly the lender's standard variable rate plus 3 percentage points.

What percentage of my income should go on a mortgage?

Aim to keep your mortgage payment below 28% of your net (take-home) monthly income for a comfortable budget. Between 28% and 35% is workable but stretched. Above 40% of net income, the household becomes mortgage-poor: pension contributions usually stop, emergency funds run dry, and any income wobble or boiler repair becomes a crisis. Use net income, not gross, when running the numbers.

What extra costs do I need to budget for when buying a house?

Budget 3-5% of the property price for non-deposit costs. That covers Stamp Duty Land Tax (zero to 12% depending on price and whether you are a first-time buyer), legal fees of £1,200 to £2,500, a survey at £400 to £1,500, a possible mortgage product fee of up to £999, and £500 to £2,000 for removals plus immediate purchases. The deposit alone is rarely the full upfront bill.

How much deposit do I need to buy a house in the UK?

The minimum deposit on most mortgages is 5% (95% LTV), but rates typically step down at 90%, 85%, 75% and 60% LTV. The rate spread between bands varies by lender and market conditions, often in the region of 0.2 to 0.5 percentage points. The illustrative impact on a £300,000 mortgage of dropping a band can be in the order of tens of pounds per month, though the actual saving depends entirely on the rates available when you apply. If you are within a few thousand pounds of the next LTV band, it is usually worth comparing live quotes at both LTVs before deciding.

What is the LISA property price limit?

The Lifetime ISA can only be used to buy a property worth up to £450,000 for first-time buyers. Withdrawing LISA funds for a property above that cap triggers a 25% withdrawal penalty, which wipes out the 25% government bonus and takes a small slice of your own contribution on top. The £450,000 cap has not moved since 2017 and bites hardest in London and parts of the South East.

Should I borrow the maximum amount a lender offers?

In our view, rarely a good idea, though only a regulated mortgage adviser can tell you what's right for your circumstances. The lender's affordability assessment is designed around their risk and volume targets, not your retirement plan. Households that buy at the top of the lender's range often report years with no pension contributions, no holidays, and no emergency fund. Many UK budgeting guides treat 25-35% of net income as a sustainable mortgage range, while a lender may approve something closer to 50%. The gap between those two numbers is the gap between owning a house and being owned by one.

What is shared ownership and is it worth it?

Shared ownership lets you buy 25% to 75% of a property and pay rent on the remainder to a housing association. For buyers priced out of full ownership in expensive areas, it is often the only realistic route to building any housing equity. The downsides are real: a service charge, restricted resale, and staircasing costs when you buy further shares. It is rarely the cheapest option in the long run, but it can be the only one that gets you onto the ladder this decade rather than next.

How much house can I afford on a £50,000 salary?

A single applicant on £50,000 gross will be offered roughly £200,000 to £225,000 by most UK lenders (4 to 4.5x income), reduced by any existing credit commitments. A few lenders will stretch to £275,000 (5.5x) for higher earners, but £50,000 sits below most of those thresholds. With a 10% deposit that is a property budget of about £225,000 to £250,000. Whether you should buy at the top of that range is a different question: 35% of your net income on the mortgage starts to bite.

Do lenders count bonuses and overtime?

Some of it, sometimes. Most UK lenders include a percentage of regular guaranteed bonus or commission (often 50%) and either some or none of overtime, depending on how consistent the income has been over the last 12 to 24 months. One-off discretionary bonuses are usually ignored. Self-employed applicants are assessed on two to three years of tax returns or SA302s, with the lender typically taking the lower year or the average. If a chunk of your income is variable, plan for the lender counting less of it than your payslip says.

What types of mortgage should I consider?

Most UK buyers default to a 2-year or 5-year fixed rate, which locks the payment for the initial term. Trackers follow the Bank Rate plus a margin and are cheaper when rates fall, more expensive when they rise. Offset mortgages let you use savings to reduce the interest charged. The choice depends on how much rate certainty you need and whether you expect rates to fall faster than the market is pricing in. Our breakdown of UK mortgage types in 2026 walks through the trade-offs in full.