Mortgage Calculator
This mortgage calculator works out your monthly repayment, the total interest you will pay, and the full cost of your home loan over its term. Enter the amount you want to borrow, the interest rate on your mortgage offer, and the term in years — the results update instantly as you adjust any figure. It works for UK repayment mortgages, US fixed-rate home loans, and Indian home loans alike, because the reducing-balance maths is the same everywhere.
The total you are borrowing — the property price minus your deposit (down payment), before any fees are added.
The yearly rate your lender quotes. Use the actual mortgage rate on your offer, not the APR, which includes fees.
How long you will repay over. 25 years is standard in the UK; 30 is common in the US. Longer terms cut the monthly cost but increase total interest.
Monthly payment
£1,390
The amount your lender collects every month for the full term — e.g. £1,390/month on a £250,000 loan at 4.5% over 25 years.
The pure cost of borrowing — everything paid on top of the £250,000 itself, purely for the use of the lender's money.
Loan amount plus total interest — the full amount that will have left your account by the final payment.
The amount you're borrowing, unchanged by rate or term — shown here for easy side-by-side comparison with the totals above.
How to use this mortgage calculator
- 1Loan amount: enter what you will actually borrow, not the property price. If the home costs £300,000 and you have a £50,000 deposit, the loan amount is £250,000.
- 2Interest rate: use the rate on your mortgage illustration or offer letter. For a fair comparison between deals, compare like-for-like — a 4.5% five-year fix against another 4.5% fix — rather than comparing a fix against a tracker.
- 3Mortgage term: slide between 15 and 35 years to see the trade-off. Shortening the term raises the monthly payment but can save tens of thousands in interest.
- 4Read the monthly payment first, then check total interest — that second number is what the mortgage truly costs you beyond the money you borrowed.
Understanding your results
The monthly payment is the figure your lender will collect by direct debit. It covers both interest and capital repayment — in the early years most of each payment is interest, and the balance slowly tips toward capital. Total interest is often the shocking number: on a long mortgage it can approach or exceed half the amount borrowed. Total repaid is simply the loan plus that interest. Use these numbers to stress-test affordability: could you still pay if rates rose 2% at remortgage time? Slide the rate up and see. If the monthly figure strains your budget, a longer term or smaller loan is safer than hoping rates fall.
The formula
M = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)M is the monthly payment, P the loan amount, r the monthly interest rate (annual rate ÷ 12 ÷ 100), and n the number of monthly payments (years × 12). This is the standard reducing-balance (annuity) formula used by every UK, US and Indian lender for repayment mortgages. Because each payment chips away at the balance, the interest charged the following month is slightly smaller — which is why overpaying early in the term saves disproportionately more interest than overpaying late.
A worked example
A £250,000 repayment mortgage at 4.5% over 25 years: the monthly rate is 0.375% and there are 300 payments. The formula gives a monthly payment of £1,389.58. Over the full term you repay £416,875 — meaning £166,875 of interest on top of the £250,000 borrowed. Now shorten the term to 20 years: the payment rises to £1,581.62, but total interest falls to £129,590, a saving of over £37,000. Try both scenarios above — the difference between term lengths is the single biggest lever most borrowers ignore.
Notes for the UK, US and India
In the UK, remember this calculator covers the mortgage only — budget separately for stamp duty, valuation and legal fees. Most UK fixes reprice every 2–5 years, so test higher rates before committing. In the US, the same formula underpins the 30-year fixed, but property taxes and insurance are usually escrowed on top of this payment. In India, home loans are reducing-balance too; most are floating-rate linked to the repo rate, so your EMI can move during the term. Indian borrowers should also check prepayment rules — floating-rate home loans usually carry no prepayment penalty.
Frequently asked questions
How much mortgage can I afford?+
A common rule is that your mortgage payment should stay under 28–35% of gross monthly income, and UK lenders typically cap borrowing at 4–4.5 times annual salary. Use our mortgage affordability figures as a starting point, then stress-test the payment here at 2% above today's rate.
Is it better to get a longer or shorter mortgage term?+
A shorter term means higher monthly payments but dramatically less total interest — on a £250,000 loan at 4.5%, moving from 25 to 20 years saves roughly £37,000. Choose the shortest term whose payment you can comfortably sustain.
Does this calculator work for interest-only mortgages?+
No — this is a repayment (capital and interest) calculator. On an interest-only mortgage you would simply pay loan × annual rate ÷ 12 each month, and the full balance would still be owed at the end.
How much can I borrow for a mortgage?+
UK lenders usually offer 4–4.5× your annual income, more for some professions. Indian lenders typically allow EMIs up to 50–60% of net monthly income. The exact figure depends on your credit history, existing debts and deposit size.
Why is my first year's payment mostly interest?+
Because interest is charged on the outstanding balance, which is largest at the start. A £250,000 loan at 4.5% accrues about £937 of interest in month one — most of a £1,390 payment. By the final years, almost the whole payment is capital.