CURRENT POSITION
Strong affordability
Plenty of monthly room — you could absorb meaningful rate rises or life changes without strain.
Affordability check
Run the monthly numbers, plan upfront costs, and see where you sit on readiness.
MORTGAGE PAYMENT
£1,208/mo
Repayment mortgage at 5% over 30 years.
LOAN TO VALUE
90%
You are between 85% and 90% LTV. This can still be workable, but increasing the deposit may improve product choice.
TOTAL REPAYABLE
£434,826
Over the full 30-year term, including £209,826 of interest.
Monthly bills
£450
Council tax, utilities, service charge, and maintenance.
Total monthly cost
£1,658
Mortgage payment + monthly bills.
Monthly surplus
£2,429
More than 50% of income is left after housing costs. That usually suggests a healthier monthly buffer.
YOUR NUMBERS
Property + mortgage
Mortgage type
Household income
Monthly running costs
Overpayments
Pay more than your monthly payment to clear the mortgage faster and pay less interest. Changes here reflect in the chart and table below.
A fixed amount added to every monthly payment.
£
NEXT BEST MOVE
Plan upfront costs
Move-in Budget tab covers stamp duty, fees, and the buffer you'll want on completion day.
Where to go next
Now check your readiness
See how prepared you are across deposit, surplus, and the binary readiness factors.
Open readiness summaryHow to read these numbers
Loan-to-value
You are between 85% and 90% LTV. This can still be workable, but increasing the deposit may improve product choice.
Monthly breathing room
More than 50% of income is left after housing costs. That usually suggests a healthier monthly buffer.
Borrowing range uses gross annual income because lender affordability often starts from gross. Monthly surplus uses estimated take-home pay after Income Tax and employee National Insurance (England, Wales and Northern Ireland rates; Scotland has different income tax bands). Doesn’t account for pension contributions, student loan repayments, or salary sacrifice arrangements.
What lenders still check
Lenders also assess income, credit history, debts, commitments, dependants and wider affordability rules. This is a planning guide, not a mortgage offer.
Your mortgage debt over time
Your remaining debt
End-of-year balance assuming your interest rate stays the same.
| Year | Remaining debt |
|---|---|
| 0 | £225,000 |
| 1 | £221,680 |
| 2 | £218,191 |
| 3 | £214,523 |
| 4 | £210,667 |
| 5 | £206,615 |
| 6 | £202,354 |
| 7 | £197,876 |
| 8 | £193,169 |
| 9 | £188,221 |
| 10 | £183,020 |
| 11 | £177,552 |
| 12 | £171,805 |
| 13 | £165,764 |
| 14 | £159,414 |
| 15 | £152,739 |
| 16 | £145,722 |
| 17 | £138,347 |
| 18 | £130,594 |
| 19 | £122,444 |
| 20 | £113,878 |
| 21 | £104,873 |
| 22 | £95,407 |
| 23 | £85,458 |
| 24 | £74,999 |
| 25 | £64,005 |
| 26 | £52,448 |
| 27 | £40,301 |
| 28 | £27,532 |
| 29 | £14,109 |
| 30 | £0 |
What this calculator includes — and what it doesn’t
Owning a home costs more than the mortgage payment alone. This calculator gives a fuller picture of monthly housing costs, but it doesn’t cover every cost of buying or living in a home.
Includes
- Monthly mortgage payment (capital + interest, repayment basis)
- Interest-only payment option
- Council tax, utilities, service charge, maintenance
- Loan-to-value calculation + banded guidance
- Borrowing range using both incomes (4–4.5×)
Does not include
- Buildings, contents, or life insurance
- One-off buying fees (legal, survey, stamp duty — see Move-in Budget tab)
- Mortgage broker fees
- Broadband, food, subscriptions, and wider living costs
What affects your mortgage payment?
Four levers move your monthly mortgage payment up or down. Adjusting any one of them changes the result.
Interest rate
A higher rate means more interest each month. Even a 1% difference can shift the payment meaningfully on a typical first-time buyer mortgage.
Mortgage term
A longer term spreads the loan over more months, lowering each payment but increasing total interest paid over the life of the mortgage.
Deposit size and loan-to-value
A bigger deposit lowers the loan amount and the loan-to-value ratio. Lower LTV often unlocks better interest rates.
Repayment vs interest-only
Repayment mortgages clear the loan over the term; interest-only payments are lower but don’t reduce the loan itself, so you’d still need a repayment plan at the end.
How much should you leave after housing costs?
There’s no single right answer, but the percentage of your household income left over after housing is a useful guide:
- 50%+ left overHealthier footing — room for savings, surprises, and everyday spending.
- 20–50% left overWorkable, but it may feel tight. Less room for savings or unexpected costs.
- Under 20% left overStretched. Most of your income would go on the home itself.
These are rough guides, not financial advice. Your situation may allow a different balance.
Mortgage calculator FAQs
Quick answers to the questions most first-time buyers have when estimating monthly mortgage costs.
How much could I borrow?+
Lenders typically offer 4–4.5× combined income, less any fixed monthly commitments. The borrowing range shown here uses both incomes if you enter them. Stress tests, deposit size, and credit history can push the actual figure up or down.
Why does the borrowing range use gross income?+
Lenders affordability-test against gross income before tax. Take-home pay still matters for monthly surplus, but the headline “how much can I borrow” figure is gross-driven.
Why does the monthly surplus use take-home pay?+
Surplus is what’s left in your bank account after housing — so it has to be calculated from take-home (net) pay, not gross. We deduct Income Tax + National Insurance using current England/Wales/NI bands.
What is loan to value?+
Loan to value (LTV) is the loan amount as a percentage of the property price. £200,000 borrowed on a £250,000 property is 80% LTV. Lower LTV usually unlocks better interest rates.
How is a mortgage payment calculated?+
On a repayment mortgage, your monthly payment is based on the loan amount, the interest rate, and the term length. Each payment covers some interest and some of the loan itself, so the balance reduces over time. Switching to interest-only uses a simpler interest × balance calculation — typical for BTL and short-hold flips.
What interest rate should I use?+
Use a rate close to what’s currently being offered for the loan-to-value you’re aiming at. Compare a few lender rates or speak to a mortgage broker. Trying a slightly higher rate as well shows how sensitive your figures are to rate changes.
Is this an official mortgage offer?+
No. This is an estimator to help you plan and compare scenarios. An actual mortgage offer comes from a lender after a full affordability check, credit check, and property valuation.
Tie this check to your full plan
The Buyer Planner connects Affordability Stress Test, Document Readiness, and Conveyancing Dashboard — turning this snapshot into a tracked plan you can return to.