Most buyers just want a simple answer to how much they can borrow based on their salary level. The honest answer is that there is no single figure. It depends on your deposit, income, credit commitments, household costs, lender criteria and the mortgage rate available at the time you apply. That said, scenario planning can give you a useful starting point.

A £300,000 mortgage could require a household income somewhere around £55,000 to £67,000, based on typical income multiples between around 4.5 and 5.5 times salary. Some lenders may offer more, some may offer less, and affordability checks can reduce borrowing even where the income looks strong on paper. For example, a single applicant earning £60,000 with little debt may be in a very different position from two applicants earning £60,000 combined but with childcare costs, car finance and credit card balances.

How much salary might I need for different mortgage amounts?

As a rough planning guide, a £200,000 mortgage may need household income of around £36,000 to £45,000, while a £250,000 mortgage may need around £45,000 to £56,000. For a £300,000 mortgage, a broad planning range could be around £55,000 to £67,000. A £350,000 mortgage may need around £64,000 to £78,000, and a £400,000 mortgage may need around £73,000 to £89,000.

These figures are not guarantees. They are broad examples to help you start thinking about affordability. The final amount you can borrow will depend on the lender’s assessment of your full circumstances, including your deposit, credit commitments, income type and monthly outgoings.

Why your deposit changes the picture

Your deposit affects how much you need to borrow and which mortgage deals may be available. If you are buying a £300,000 property with a 5% deposit, you would need around £15,000 upfront and a mortgage of about £285,000. With a 10% deposit, you would need around £30,000 upfront and a mortgage of about £270,000. With a 15% deposit, you would need around £45,000 upfront and a mortgage of about £255,000.

That difference matters. A larger deposit can reduce the mortgage amount, may improve the range of products available, and can lower the monthly payment. A smaller deposit can help you buy sooner, but it usually means a larger mortgage and potentially higher monthly costs.

What about monthly payments?

The monthly payment is often more important than the headline mortgage amount. For example, a mortgage of around £300,000 over a long repayment term could easily sit somewhere in the region of £1,500 to £1,700 per month, depending on the rate and term. A higher rate, shorter term or larger mortgage would increase that payment.

This is why buyers should avoid judging affordability on salary alone. A lender might approve a mortgage, but you still need to feel comfortable paying it alongside normal living costs such as council tax, utilities, insurance, commuting, childcare, subscriptions, food, car costs, savings and general household spending.

Single income vs joint income

A single applicant usually has less room for error because the mortgage depends on one income. If that income changes, the whole household budget can be affected. Joint applicants may have more borrowing power because the lender can assess two incomes, but joint applications can also come with higher commitments. Childcare, loans, car finance, credit cards and dependants can all affect affordability.

This is why two households with the same income can receive different mortgage outcomes. A couple earning £35,000 each may look stronger than a single applicant earning £70,000 in some cases, but not always. The detail matters.

What checks will lenders carry out?

Lenders will usually look at your income, deposit, credit history and regular financial commitments. They will also consider the property, the mortgage term, the type of income you receive and whether the mortgage remains affordable if rates or circumstances change.

Common checks include basic salary, bonus, overtime or commission, self-employed income history, credit cards, loans, car finance, childcare, dependants, credit score, payment history, deposit size, mortgage term and property type. If your income is variable, you are self-employed, have recent credit issues, or want to borrow near the upper end of affordability, advice becomes particularly important.

Costs to plan for beyond the deposit

The deposit is only one part of buying a home. You may also need to budget for solicitor fees, valuation or survey costs, mortgage arrangement fees, moving costs, insurance, initial repairs, furniture and an emergency fund. For leasehold properties, service charges and ground rent may also affect affordability.

A buyer who uses every available pound for the deposit may find the first few months after moving much tighter than expected, even if the mortgage itself has been approved.

A sensible way to plan

Before you start making offers, it helps to look at three scenarios. First, work out your safer option. This is the property price and mortgage payment that leaves you with breathing room. Then work out your comfortable option. This is the level where the mortgage feels manageable and still allows you to save and cover normal costs. Then look at your stretch option. This is the upper end of what may be possible, but it needs careful checking because even small changes in rate, bills or income can make a difference.

The right mortgage is not always the biggest mortgage available. It is the one that fits your income, deposit, lifestyle and plans with enough room for normal household costs.

When should you speak to a mortgage adviser?

It is worth speaking to an adviser before you rely too heavily on online calculators or start viewing homes at the top of your assumed budget. A mortgage adviser can help you understand how different lenders may assess your income, deposit, debts and credit profile, and they can show how your borrowing position changes at different deposit levels and mortgage terms.

This can be especially useful if you are buying with a smaller deposit, have variable income, are self-employed, have existing debts, or are trying to understand whether a single or joint application gives you the better route.

If you are asking, “How much salary do I need for a £300k mortgage?”, the useful answer is not just one salary figure. You need to look at the mortgage amount, deposit, monthly payment, lender affordability checks and your wider household budget.

A £300,000 mortgage may be realistic for some households and too much for others. The best place to start is with a clear affordability conversation before you commit to a property search or make an offer.

Grange Mortgages can help you compare different mortgage scenarios and understand what may be possible based on your income, deposit and circumstances.