UK Mortgage Calculator — Monthly Payment, Overpayment & Total Interest
Work out what a UK mortgage really costs in pounds: your monthly payment, the total interest over the full term, your loan-to-value (LTV), and the date you become mortgage-free. Add a monthly overpayment to see exactly how much interest you save and how many years you knock off your term. The default rate below is 5.97% — the average 2-year fixed rate in November 2026 (Moneyfacts) — because the Bank of England raised the Bank Rate to 4.00% on 5 November 2026. It is a market average for guidance, not a quote: the rate you are offered will depend on your deposit, credit history and the lender.
Your mortgage
That's £25,000 towards the property.
Default 5.97% = average 2-year fixed, Moneyfacts, November 2026. A market average, not a quote you will necessarily be offered.
Repayment: every payment chips away at the loan, so it is gone by the end of the term.
Even £100–£200 a month can save thousands in interest. Most fixed deals allow overpaying up to 10% of the balance per year without a charge — check your lender's limit.
Your results
Amortisation summary — year by year
How your balance falls each year, including any overpayment. Figures are rounded to the nearest pound.
| Year | Paid | Interest | Capital | Balance |
|---|
Worked example
Buying a £250,000 home with a 10% deposit. Deposit £25,000, so you borrow £225,000 at 5.97% over 25 years on a repayment mortgage.
The calculator gives a monthly payment of £1,446, total interest of £208,666 and £433,666 repaid in total, with the mortgage cleared in November 2051. Your loan-to-value is 90%.
Add a £200 monthly overpayment and the same mortgage is cleared about 5 years 10 months early, saving roughly £55,594 in interest — try it above and watch the numbers move.
How it works
- Enter the property price and your deposit. The deposit can be typed as pounds or as a percentage of the price — the calculator works out the loan amount and your loan-to-value for you.
- Set the interest rate and term. The rate starts at 5.97%, the average 2-year fixed rate for November 2026 (Moneyfacts). Use the rate cards above to try the average 5-year fixed (5.99%) or the standard variable rate (7.13%), or type the exact rate from a lender's illustration.
- Choose repayment or interest only. A repayment mortgage clears the loan by the end of the term. Interest only keeps the monthly payment lower but leaves the full loan to repay at the end.
- Add a monthly overpayment. Every extra pound goes straight off the loan balance, so you pay interest on less each month. The results show the interest saved, how much sooner you are mortgage-free, and a year-by-year amortisation summary.
How the monthly payment is calculated: for a repayment mortgage the calculator uses the standard amortisation formula — payment = loan × r × (1 + r)n ÷ ((1 + r)n − 1), where r is the monthly rate (annual rate ÷ 12) and n is the number of monthly payments. For interest only, the monthly payment is simply the loan × r. The balance is then simulated month by month, with your overpayment applied on top, to produce the payoff date, total interest and year-by-year figures.
Why LTV matters: lenders price mortgages in LTV bands — 95%, 90%, 85%, 75% and 60% are the common steps. Dropping into a lower band with a slightly bigger deposit can unlock a noticeably cheaper rate, which is why this calculator shows your LTV next to every result.
Frequently asked questions
How much will a £225,000 mortgage cost per month in 2026?
At 5.97% — the average 2-year fixed rate in November 2026 (Moneyfacts) — a £225,000 repayment mortgage over 25 years costs £1,446 a month, with £208,666 of interest over the full term. The same loan on the average standard variable rate of 7.13% would cost roughly £1,609 a month, which is why most borrowers fix rather than drift onto the SVR.
How much interest does overpaying save?
It depends on the amount, the rate and how long is left on the mortgage. On the worked example above (£225,000 at 5.97% over 25 years), overpaying £200 a month saves about £55,594 in interest and clears the mortgage around 5 years 10 months early. Even £100 a month saves roughly £32,449. Enter your own overpayment above to see your exact figures.
What is a good loan-to-value (LTV) in the UK?
LTV is the loan as a percentage of the property price. The best rates are usually at 60% LTV or below, with meaningful improvements at 75% and 85% too. First-time buyers can borrow at 90% or 95% LTV, but rates are higher because the lender takes more risk. On a £250,000 home, moving from a 10% deposit (90% LTV) to a 15% deposit (85% LTV) means finding an extra £12,500 — and can be worth it if it drops you into a cheaper rate band.
Should I choose a 2-year or 5-year fixed rate?
In November 2026 the average 2-year fix is about 5.97% and the average 5-year fix about 5.99–6.00% (Moneyfacts) — almost identical. A 2-year fix lets you re-fix sooner if the Bank Rate (4.00% since 5 November 2026) falls, but you pay product fees more often and risk rates being higher when the deal ends. A 5-year fix costs little more here and buys five years of payment certainty. The right choice depends on how much you value stability versus flexibility.
What happens when my fixed deal ends?
You automatically move onto your lender's standard variable rate — about 7.13% on average in November 2026 — which usually pushes your payment up sharply. On a £225,000 balance that jump can add around £163 a month. Most borrowers remortgage or switch to a new product with their existing lender a few months before the deal ends to avoid paying the SVR.
Is interest only ever a good idea?
Interest only keeps monthly payments low because you never repay the loan itself during the term — on £225,000 at 5.97% you would pay £1,119 a month instead of £1,446 — but you still owe the full £225,000 at the end and need a credible plan to repay it, such as investments or selling the property. Lenders apply strict criteria, and this calculator assumes any overpayment you add goes towards clearing that final balance early.
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