How Much House Can You Actually Afford? A Clear Framework

When you apply for a mortgage, the bank works out the most it can safely lend you without you defaulting. Your job is different: to work out the most you can borrow while still living the life you want, sleeping well at night and not being one redundancy notice away from financial trouble.

These are not the same number, and the gap between them is where many people who end up "house poor" go wrong.

How Banks Decide

Banks look at your income, your existing debts and how much of the purchase price you can pay yourself. In the Nordic countries they also test whether you could still afford the loan if interest rates rose. Finnish banks are expected to check that you could manage the payments at an interest rate of 6% over 25 years, and Swedish banks use a similar stress-test rate, the kalkylränta. A common international rule of thumb, the 28/36 rule, says the mortgage payment should not exceed 28% of gross monthly income and all debt payments together 36%.

On a gross income of €4,000 a month, 28% is €1,120. Notice what such rules leave out: income tax, pension contributions, childcare, groceries, transport, insurance and everything else that comes out of your actual take-home pay.

A More Realistic Method: Start From Your Net Income

A more cautious and practical approach starts from your real take-home pay:

• Work out your average monthly net income after all deductions.
• List your fixed non-housing costs: car, loans, subscriptions, childcare.
• Estimate your variable costs honestly: food, transport, clothes, hobbies.
• Decide how much you want to save each month for emergencies, retirement and other goals.
• What remains is the most you can comfortably spend on housing.

Many financial planners suggest keeping the mortgage payment to no more than 25–30% of your net income, and some recommend closer to 20% to leave real room for saving and the unexpected.

Example: Same Income, Very Different Situations

Both earn the same salary, and a bank might offer them similar loans. But after their existing commitments, Person B has far less room for housing costs. The bank's offer is a ceiling. Your own budget is what matters.

The Price-to-Income Ratio

A quick rule of thumb for the price of a home, rather than the monthly payment, is the price-to-income ratio. Historically, a price of 3–4 times the household's annual gross income has been sustainable. More than 5 times is generally considered stretched, and more than 6 times leaves little margin for higher rates, a loss of income or unexpected costs.

In many European cities, especially capitals, prices are well above these historical levels, which is why the monthly calculation matters more than the ratio alone. A low ratio does not guarantee comfort if interest rates are high, and a higher ratio can be manageable when rates are low.

Remember the Costs Beyond the Mortgage

Owning a home brings costs that renting does not. Budget for:

• Housing company or cooperative charges for an apartment (yhtiövastike in Finland, avgift in Sweden), which can rise when the building needs renovation
• Property tax, which varies by municipality and country
• Home insurance
• Maintenance and repairs for a house; a common guideline is about 1% of the property's value a year
• Heating, water and electricity, if they are not included in the charges
• Moving and furnishing, often underestimated by first-time buyers

Adding these to the loan payment gives a much more realistic picture of your total monthly housing cost.

When to Borrow Less Than the Bank Offers

Just because a bank will lend it does not mean you should borrow it. Consider borrowing less if:

• the monthly payment would be more than 30% of your net income;
• you would have less than three to six months of expenses saved as a buffer after the purchase;
• the plan depends on two incomes and you are not confident both are secure;
• you have not tested the payment at a rate two or three percentage points higher than today's.

Summary

The right mortgage is not the largest one you can get. It is the largest one that fits comfortably within your net income after your other commitments, still lets you save, and leaves a buffer for the unexpected. Treat the bank's offer as a ceiling, not a target, and work backwards from your own budget to a price. The result is a home that improves your financial life instead of straining it.