Calculator
Monthly repayment calculator
Work out your monthly payment for a given loan, rate and term — and see the balance fall over time. The first few years of a repayment mortgage are mostly interest; the last few are mostly capital. This calculator shows that split year-by-year.
Your loan
Repayment summary
Balance over time
| End of year | Interest paid | Capital paid | Balance remaining |
|---|---|---|---|
| Year 1 | £11,247 | £3,300 | £221,700 |
| Year 5 | £10,513 | £4,034 | £206,709 |
| Year 10 | £9,361 | £5,186 | £183,198 |
| Year 20 | £5,979 | £8,569 | £114,127 |
| Year 30 | £389 | £14,159 | £0 |
Monthly payment uses the standard amortisation formula with interest compounded monthly. Your lender may present a slightly different figure (pence-level differences). Not financial advice. Read about mortgage types →
Capital-and-interest vs interest-only
A standard repayment mortgage in the UK is capital-and-interest: each month you pay interest on the outstanding balance plus a little bit of the capital. By the end of the term the loan is gone.
Interest-only mortgages only cover the interest each month — the loan balance never reduces. You still owe the original capital at the end of the term, and you need a repayment vehicle (investments, savings, eventual sale) to clear it. Most UK residential mortgages must be capital-and-interest (MMR rules since 2014); interest-only is mainly a buy-to-let product.
Why the early years feel expensive
In year one of a 30-year repayment mortgage at 5% you might be paying 80% of every pound as interest and only 20% as capital. By year twenty that ratio flips. This is mathematical — interest is always computed on the remaining balance, which is still high in the early years. It is not a trick by your lender.