What next?
A monthly payment is only part of the picture. These are the numbers people usually need next, in the order they tend to need them.
External links are marked and open in a new tab. We are not a broker and receive no commission on any mortgage you take out — always check a deal against the lender’s own terms.
How to use this calculator
- Enter the property price, then your deposit — as a cash amount, or switch to % of price if you are thinking in terms of a 10% or 20% deposit.
- Set the interest rate and term in years.
- Read your estimated monthly payment.
What your result means
The monthly payment is what you would repay each month on the amount borrowed (price minus deposit) at your chosen rate and term. A bigger deposit or shorter term cuts total interest but raises the monthly cost. This is a repayment-mortgage estimate only — it excludes fees, insurance and any rate change after a fixed period ends.
Why this one is different
Six purchases at 90%, 80% and 75% loan-to-value are worked out in full on a linked page, so you can see what a bigger deposit actually does before touching an input. Every calculation round-trips through the URL, so a link reopens with your figures intact, and the worked example below is script-verified against the live tool.
Why a 0.5% rate change is worth thousands
On a mortgage, tiny rate differences compound over decades into eye-watering sums. The same house can cost wildly different amounts depending on your rate, term and deposit — which is why lenders reward a lower loan-to-value with better deals.
Playing with the deposit and term here shows the trade-off in seconds: a bigger deposit or shorter term raises the monthly payment but can slash the lifetime cost.
Historic interest rates, and why they matter here
The rate you can borrow at is not a fixed feature of the world — it moves, and over a 25-year term it will move several times. The figures below are the Bank of England’s Bank Rate, the benchmark UK lenders price against. A mortgage rate always sits above it: typically half a point to two points for a new fixed deal, and considerably more on a lender’s standard variable rate once a fix ends.
The practical use of that history is stress-testing. A fix protects you for two or five years, not for the term, so the rate that decides your payment in 2031 is one nobody knows today. Run your figures here at your actual rate, then run them again two and four points higher: if the higher payment is survivable, the mortgage is. Lenders apply a version of the same test before they lend, and the gap between the two payments is the honest measure of how exposed you are.
How it works
Your deposit is subtracted from the property price to give the loan amount. That balance is repaid with interest in equal monthly instalments over the term, using the standard amortisation formula. Loan-to-value (LTV) — the loan as a percentage of the property price — affects the rates lenders will offer you.
Formula
P = loan (price − deposit), r = monthly rate, n = months.
Frequently asked questions
What is a good LTV?＋
Lower is better for you. A 60% LTV usually unlocks the best rates; above 90% rates rise and choice narrows. A bigger deposit lowers LTV.
Does this include fees or insurance?＋
No. It shows principal and interest only. Product fees, buildings insurance and any early-repayment charges are extra.
What is the difference between repayment and interest-only?＋
A repayment mortgage clears both interest and capital, so the balance reaches zero at the end of the term — that is what this calculator models. An interest-only mortgage pays just the interest, leaving the full capital owed at the end, which you must repay by other means. Payments are far lower, and the balance does not fall at all.
What happens when my fixed rate ends?＋
You move to the lender’s standard variable rate unless you remortgage, and that rate is usually considerably higher. Payments can rise sharply. Rerun this calculator with the likely new rate a few months before your deal expires so the increase is not a surprise.
How much deposit do I actually need?＋
Most lenders require at least five per cent, but the rate improves at each loan-to-value band — typically ninety, eighty-five, seventy-five and sixty per cent. Pushing your deposit just past a band boundary can cut the rate meaningfully.
Example calculation
A £250,000 repayment mortgage at 5% APR over 25 years (300 months):
Payment = £250,000 × r(1+r)300 ÷ ((1+r)300 − 1)
Monthly payment ≈ £1,461
Total repaid ≈ £438,400 · interest ≈ £188,400
Related calculators
Assumptions & limitations
Every figure here comes from a simplified model. Keep these limits in mind when reading your result:
- Assumes a fixed rate over the full term.
- Excludes property taxes, insurance, and product or legal fees.
- Variable and fixed-then-revert deals will change your payment over time.
- Assumes you pay exactly the contractual amount each month. Paying more shortens the term and cuts the interest sharply — the mortgage overpayment calculator works out by how much.
Further reading
Formula & reference
Worked answers for common purchases
Each shows the payment, the LTV, and what a different deposit, term or rate would change — and opens this calculator with the figures already filled in. All at 4.5% over 25 years.