A bigger mortgage. But what’s left to live on?
A lender’s maximum isn’t necessarily your comfortable budget.
Extending your mortgage term can bring the monthly payment down and potentially open up more borrowing. But it also means more years of repayments—and usually more interest overall.
In this video, Matthew follows a £60,000-income example where a 35-year mortgage leaves just £87 a month after illustrative living costs.
Try your own numbers below. Compare terms, adjust your spending and see what happens when life gets a little more expensive.
Propillo · The real-life check
You can borrow it.
Can you live with it?
Compare mortgage terms—and see what remains for the rest of life.
01 · Your income and the home
Start with the numbers.
Traditional budgeting advice often suggested keeping mortgage payments around one-third of take-home income. That leaves the rest for living costs, savings and other spending.
It is not a universal affordability rule, and it may feel unrealistic for many buyers today. A mortgage can consume a much larger share of income—even if it passes a lender’s assessment. But does being allowed to borrow that much make it a good idea?
£1,281 One-third of the monthly take-home entered above02 · Life still costs money
What else goes out each month?
Starting amounts are an illustrative budget, not official averages. Replace them with your own costs. A zero is not a recommendation to omit that expense.
03 · Compare the monthly reality
Same mortgage. Different terms.
25 years
Monthly mortgage payment £2,579 67% of take-home35 years
Monthly mortgage payment £2,255 59% of take-home“Left each month” is after the costs you entered. Missing expenses are not automatically allowed for. A positive figure does not confirm lender approval or mean the mortgage is suitable.
04 · The price of more time
What changes over the full term?
35 years reduces the payment by £324 a month but adds £173,546 in interest.
Both terms use the same entered rate throughout. These are illustrations, not predictions of future rates. Excludes fees and overpayments. Interest is not the lender’s profit.
Before you stretch, check the whole picture.
Allow for repairs, savings, credit commitments and suitable protection. Think about what happens if your income falls or your mortgage rate rises. A budget that balances today is only the starting point.
Explore your circumstances and what needs checking before you commit. This tool is a personal-budget illustration, not a lending decision. Your home may be repossessed if you do not keep up repayments on your mortgage.
Assumptions and sources
Automatic take-home uses a simplified 2026/27 England/Wales/Northern Ireland Income Tax calculation and a 6%/2% National Insurance proxy based on sole-trader Class 4 rates. It is not a complete personal tax calculation and can overestimate take-home for employees. It does not account for Scottish tax bands, pensions, student loans, benefits or other income. Enter your actual monthly take-home where possible.
Income Tax: £12,570 personal allowance, reduced by £1 for every £2 above £100,000; 20% basic, 40% higher and 45% additional rates. NI proxy: 6% between £12,570 and £50,270, then 2%. The default £60,000 example produces approximately £3,842.62 a month.
Repayment mortgage, monthly interest equal to annual nominal rate divided by 12. Mortgage amount is property price minus deposit. Total interest assumes the entered rate for the entire term. Term choices shown are illustrations, not confirmation of availability. Figures are rounded independently.
The one-third rule is a rough personal-budget guideline, not a universal lender limit. Initial living costs are illustrative, not ONS averages. Inputs are not saved or submitted by this tool.
See How Lenders Are Likely to Read Your Case
Most borrowers compare rates before they know whether a lender will actually like their case.
That’s how people waste time with the wrong bank, get weaker offers, or end up with avoidable declines.
The readiness check gives you an early read on how your case is likely to land, where the pressure points are, and whether lender choice needs more care.
- Avoid wrong lenders
- Spot pressure points
- Understand case fit
- Check before applying
See How Lenders Are Likely to Read Your Case
Mortgage Readiness Check
See how lenders will read your case.
Whether the income pattern looks stable enough to rely on, and how much of it they are prepared to include.