Mortgage Overpayment Calculator
See the interest saved and the new end date from overpaying, set against keeping the cash in savings.
Many lenders allow 10% a year without an early repayment charge. Your mortgage offer says what yours is.
Usually the rest of your fixed or tracker deal.
Before tax.
£200,000 at 4.5% over 25 years
| Keeping to the current payment | |
|---|---|
| Monthly payment | £1,111.66 |
| Last payment September 2051 | 25 years |
| Total interest | £133,499.49 |
| Overpaying | |
| Paid each month | £1,311.66 |
| Last payment August 2045 | 18 years and 11 months |
| Total interest | £97,219.09 |
| Interest saved | |
| Interest keeping to the current payment | £133,499.49 |
| Less interest when overpaying | −£97,219.09 |
| Interest saved | £36,280.40 |
Overpaying against saving at 4%
| Savings at September 2051, with the mortgage cleared either way | |
|---|---|
| Overpay, then save the payment once the mortgage is cleared | £108,634.43 |
| Less: keep the same cash in savings instead | −£101,769.62 |
| Better off overpaying, before tax | £6,864.81 |
Both sides spend the same each month. Overpaying clears the mortgage sooner and then puts the payment into savings; saving keeps the lump sum and overpayments in savings while the mortgage runs its full term. Savings interest can be taxed: part is covered by the Personal Savings Allowance, which depends on your tax band, and interest inside an ISA is tax-free. Money paid off a mortgage is also harder to get back than money in savings.
- A capital repayment mortgage, with interest worked monthly at the annual rate divided by 12.
- The rate stays the same for the whole term. In practice it changes when a deal ends.
- Overpayments reduce the term and keep the monthly payment the same. Some lenders reduce the payment instead.
- The allowance is measured against the balance at the start of each year from today. Lenders measure it in different ways.
- Savings interest is compounded monthly at the AER you enter, before tax.
- Interest-only and part-and-part mortgages, and offset mortgages.
- The amount of any early repayment charge, and fees for changing deal.
- Which product or lender suits you. This is a general illustration and not a recommendation.
What it does
Enter your balance, rate and remaining term, then a monthly overpayment or a lump sum. It shows the interest saved, when the mortgage clears, whether you would go over your yearly overpayment allowance, and how it compares with saving the same money.
An estimate is useful. Running it against your real accounts is better, and takes about ten minutes.