How Much House Can I Afford?

This calculator estimates your borrowing power based on the same factors lenders use. It gives you a starting point—a realistic range to search within.

The important word is "estimate." Every lender has different criteria. Your actual mortgage offer may be higher or lower depending on factors this calculator can't account for: your credit history, employment type, property type, and the specific lender's appetite for risk.

Use this to calibrate your search, not as a guarantee. When you've got your affordability range, the next step is understanding what else affects the process, like how much deposit you'll need and the overall costs of buying.

Understanding your results

The calculator shows two numbers: maximum borrowing and comfortable borrowing. These are different, and that difference matters.

Maximum borrowing

This is what a lender might approve based on the standard income multiple (typically 4-4.5 times salary). It's the upper limit of what you could potentially borrow.

But here's what the numbers don't tell you: lenders approve maximums they think you can technically repay. That doesn't mean that maximum is comfortable—or wise.

Comfortable borrowing

This is 80% of the maximum, reflecting what most financial advisers consider a sensible ceiling. It leaves room for:

• Interest rate increases on your next mortgage deal
• Life changes (children, career changes, unexpected costs)
• Actually enjoying your income rather than sending it all to the bank

The percentage that matters

More useful than the raw borrowing figure is what your mortgage payment represents as a percentage of your take-home pay.

These aren't hard rules. Someone with no children, low expenses, and secure income can handle a higher percentage than someone with three kids, a car payment, and variable income.

How we calculate this

The calculator uses a standard methodology based on how UK lenders assess affordability.

Income multiple

According to FCA mortgage conduct rules, most lenders use a multiple of 4-4.5 times annual income as their base calculation. Some lenders offer higher multiples (up to 5.5x) for specific professions like doctors or solicitors, or in certain circumstances. Others are more conservative.

This calculator uses 4.5x as the base, which represents the higher end of standard lending.

Joint income

If you're buying with someone else, your incomes are combined. Two people earning £40,000 each have borrowing power equivalent to one person earning £80,000.

Debt adjustment

Your existing monthly debt payments reduce your borrowing power. Lenders look at your "debt-to-income ratio"—how much of your income is already committed.

The calculator reduces your maximum borrowing based on annual debt payments. A £300/month car payment (£3,600/year) might reduce your borrowing capacity by £15,000-£20,000.

Deposit impact

Your deposit doesn't directly affect how much you can borrow (that's based on income), but it affects the property price you can afford. More deposit = same borrowing + higher budget.

What this doesn't include

No calculator captures everything. Here's what this one can't account for:

Individual lender criteria. Some lenders are stricter; others more flexible. Specialist lenders may offer different terms for self-employed borrowers, contractors, or complex income situations.

Credit score impact. Your credit history significantly affects your options. Poor credit may mean lower borrowing limits or no mortgage at all.

Employment type. Contractors, self-employed people, and those with variable income face additional scrutiny. Lenders may use lower income figures for their calculations.

Property type restrictions. Some property types (ex-council, non-standard construction, short leases) have restricted lending options. The property you want to buy matters.

Scheme-specific rules. Shared Ownership, First Homes, and other schemes have their own affordability rules that may differ from standard mortgages. Understanding first-time buyer benefits can help you identify if you qualify for special support.

What to do with your number

Your affordability result is a starting point. Here's how to use it:

Search properties in your range

Start looking at properties 10-20% below your maximum. This gives you negotiating room and accounts for properties often selling above asking price in competitive markets.

Get mortgage in principle

This is the next concrete step. A Mortgage in Principle (MIP) from an actual lender confirms your borrowing power and signals to sellers you're serious.

An MIP involves a soft credit check and typically takes 24 hours to a few days. It's usually valid for 60-90 days and doesn't commit you to anything.

Don't stretch to maximum without margin

The calculator shows what you could borrow. That doesn't mean you should borrow it all.

Ask yourself: if interest rates rise 2% when you remortgage in 5 years, can you still afford the payments? If your circumstances change—job loss, illness, family changes—do you have breathing room?

The buyers who end up happiest are usually those who bought slightly below their maximum, not those who stretched to the limit.

Common questions

Why is my number different from other calculators?

Different calculators use different assumptions. Some use 4x income; others use 4.5x or 5x. Some include stress testing for rate rises; others don't. Some factor in regional variations; others use national averages. Your actual mortgage offer will depend on the specific lender's criteria.

Can I actually borrow this much?

Possibly. This calculator gives a realistic estimate, but your actual offer depends on factors it can't measure: credit history, employment type, property details, and the specific lender's criteria. A mortgage in principle from an actual lender gives you more certainty.

What if I have irregular income?

Lenders treat variable income more conservatively. If you receive bonuses, commission, or overtime, lenders typically use an average or a percentage rather than the full amount. Self-employed borrowers usually need 2-3 years of accounts, and lenders may use a lower figure than your recent income.

Do bonuses count?

Usually, yes—but not at full value. Most lenders include some percentage of regular bonuses (often 50-75% of a two-year average). One-off bonuses are typically excluded. Commission and overtime are treated similarly to bonuses.

Data and methodology

This calculator uses the following assumptions:

• Base income multiple: 4.5x combined annual income
• Debt adjustment: Reduces maximum by 12x annual debt payments
• Monthly payment estimate: Based on current average 5-year fixed rates
• Comfortable threshold: 80% of maximum borrowing

Interest rates used for monthly payment estimates are updated monthly and reflect typical high-street lender offerings for 90% LTV mortgages.

Sources: Bank of England base rate, UK Finance mortgage data, major lender rate sheets.

Last updated: December 2025