Mortgage repayments
Work out the monthly cost of a repayment mortgage, plus the total interest over the life of the loan.
The property
Over the full term
Assumes a capital-repayment mortgage at a fixed rate for the whole term. Real mortgages re-fix every few years, so the rate — and your payment — will usually change.
What the repayments really add up to
Borrow £255,000 at 4.5% over 25 years, the default above, and the payment is £1,417 a month. Multiply it out and the quiet number appears: £425,212 repaid in all, of which £170,212 is interest. Two thirds of the price of the house again, paid for the privilege of spreading the rest. None of this is a scandal, it's simply what long money costs, but seeing the total changes how you negotiate the two numbers that drive it.
Rate and term, the two levers
Rate first: one percentage point matters more than it sounds. At 5.5% the same loan costs £1,566 a month, £149 more every month and roughly £1,800 a year, which is why a remortgage at the end of a fixed deal deserves shopping around rather than rolling onto the standard variable rate. Term second: stretching to 30 years drops the payment to £1,292 and lifts the total repaid to £465,137. The £125 of monthly breathing room costs almost £40,000 over the life of the loan. Sometimes that trade is right, especially early on. It should just never be invisible.
The costs around the mortgage
The deposit and the monthly payment get all the attention, and then stamp duty, legal fees and surveys arrive in the same week. Price the tax with the stamp duty calculator, sense-check what a lender will offer against the affordability calculator, and once you're in, the overpayment calculator shows how even £100 a month attacks that £170,212 of interest from the front, where it hurts the lender most.
Common questions
How are monthly mortgage repayments calculated?
From three things: the amount borrowed, the interest rate and the term. The calculator uses the standard repayment formula so that equal monthly payments clear both the loan and the interest over the full term.
How much difference does the interest rate make?
A large one. Even a single percentage point can move a typical monthly payment noticeably and add thousands of pounds over a 25-year term, which is why the calculator also shows the total interest.
Should I choose a shorter term?
A shorter term means higher monthly payments but far less total interest, while a longer term lowers the monthly cost and increases what you pay overall. Try a few terms to see the trade-off.
These results are estimates for general information only and are not financial advice. Check every figure yourself and seek appropriate advice from a qualified professional before making any decision. Read the full disclaimer.