How Much Mortgage Can You Actually Afford?
Learn the difference between what a lender will approve and what you can comfortably afford, plus simple rules of thumb to sanity-check your budget.
The Question Every Buyer Asks First
Before you fall in love with a listing, it helps to know your actual budget — not just what a lender is willing to offer you, but what you can comfortably afford without stretching every month. Those two numbers are often very different.
Lender Approval vs Comfortable Affordability
Lenders calculate how much they'll approve based on your income, existing debts, and credit profile. That figure is the maximum they're willing to risk — it's not a recommendation for what you should actually spend. Many buyers who borrow right up to their approved limit end up "house poor," with little room left for savings, emergencies, or simply enjoying their income.
Two Common Rules of Thumb
| Rule | What it says | Best for |
|---|---|---|
| 28/36 rule (US-style) | Housing costs ≤28% of gross income; total debt ≤36% | Quick affordability check |
| 3-4.5x income (UK-style) | Mortgage typically capped at 3-4.5x annual income | Estimating lender limits |
These are starting points, not guarantees — actual limits vary by lender, credit history, deposit size, and local regulations.
What Actually Goes Into "Affordability"
- Deposit / down payment. A larger deposit reduces your loan amount and often unlocks better interest rates.
- Interest rate and term. A longer term lowers monthly payments but increases total interest paid over the life of the loan.
- Property taxes and insurance. These add to your monthly outgoings but are easy to forget when budgeting from the sale price alone.
- Existing debts. Car loans, credit cards, and student loans reduce how much lenders think you can safely take on.
- Maintenance and running costs. A common guideline is budgeting 1-2% of the property's value per year for upkeep.
A Simple Way to Sanity-Check the Numbers
Take your gross monthly income and multiply by 28%. That's a rough ceiling for your total housing payment (mortgage, tax, insurance combined). If your desired home pushes you well past that, either the price, the deposit, or the loan term needs adjusting.
Don't Forget the Upfront Costs
Affordability isn't only about the ongoing mortgage payment. Closing costs, legal fees, surveys, and moving expenses can add up to several thousand pounds or dollars before you even move in — budget for these separately from your deposit.
Check Your Own Numbers
Rather than guessing, run your income, deposit, and target property price through our House Affordability Calculator to see an estimated comfortable price range, or use the Mortgage Calculator to see exact monthly payments at different rates and terms.
Frequently Asked Questions
How much deposit do I actually need?
It varies by lender and loan type, but a larger deposit generally means a smaller loan, lower monthly payments, and often a better interest rate.
Should I borrow the maximum a lender offers?
Not necessarily. Lender maximums are based on risk tolerance, not your personal comfort level or other financial goals like saving and investing.
Do rising interest rates change how much I can afford?
Yes — a higher rate increases your monthly payment for the same loan amount, which can significantly reduce the property price you can comfortably afford.