Calculate Your Mortgage Overpayments
See how small overpayments could affect the interest you pay and how much sooner you could be mortgage-free.
No email required. UK focused. Results are estimates only.
Results are estimates only and not financial advice
Nice. You could own your home 6 yrs 4 mths sooner, by March 2041.
£27,412less interest- Mortgage-free
- Mar 2041
- Time saved
- 6 yrs 4 mths
- Interest without overpaying
- £82,488
- Interest with overpaying
- £55,076
Balance over time
Dashed: without overpaying. Solid with shading: with £255/mth extra. The dot on the axis is your new mortgage-free date.
Your home stretch
Milestones with overpaying. The pale band is the time you no longer pay.
- TodaySep 2026
- 25% paid offMay 2031
- Half paid offFeb 2035
- 75% paid offMay 2038
- Mortgage-freeMar 2041
- 6 yrs 4 mths sooner
- Without overpayingJul 2047
Every dot is a monthly payment
Overpaying switches off 76 payments at the end.
- 174 payments you make
- Last payment, Mar 2041
- 76 payments switched off
Shorten your term or lower your payment
The same overpayments, applied two ways. Which one happens depends on your lender.
Keep your payment, finish sooner
- Contractual payment
- £937.95 a month, unchanged
- Mortgage-free
- Mar 2041
- Interest saved
- £27,412
This is how the results above are worked out.
Keep your term, lower your payment
- Contractual payment
- £918.76 a month from Oct 2027 (now £937.95)
- Mortgage-free
- Sep 2046
- Interest saved
- £16,502
With a monthly overpayment, the payment keeps falling a little each month.
It can still end a little early, because the overpayments continue while the payment falls.
Keeping your payment and finishing sooner saves £10,910 more interest than lowering your payment, with these figures.
Many UK lenders use overpayments to shorten your mortgage term, so your monthly payment stays the same and you finish paying sooner. Some lenders will recalculate and lower your monthly payment instead, and some only do this if you ask, so check your mortgage offer or ask your lender how your overpayments will be applied.
The lower-payment figures assume your lender recalculates your payment after every overpayment, over the term you have left, and that you keep making the same overpayments.
Show the figures as a table
| Year | Ends | Balance without | Balance with | Interest paid (with) |
|---|---|---|---|---|
| 1 | Sep 2027 | £147,492 | £144,368 | £6,684 |
| 2 | Sep 2028 | £142,778 | £136,386 | £6,333 |
| 3 | Sep 2029 | £137,846 | £128,038 | £5,967 |
| 4 | Sep 2030 | £132,689 | £119,305 | £5,583 |
| 5 | Sep 2031 | £127,294 | £110,172 | £5,182 |
| 6 | Sep 2032 | £121,651 | £100,619 | £4,762 |
| 7 | Sep 2033 | £115,749 | £90,627 | £4,323 |
| 8 | Sep 2034 | £109,576 | £80,176 | £3,864 |
| 9 | Sep 2035 | £103,120 | £69,244 | £3,384 |
| 10 | Sep 2036 | £96,367 | £57,811 | £2,882 |
| 11 | Sep 2037 | £89,303 | £45,853 | £2,357 |
| 12 | Sep 2038 | £81,915 | £33,345 | £1,808 |
| 13 | Sep 2039 | £74,188 | £20,262 | £1,233 |
| 14 | Sep 2040 | £66,106 | £6,579 | £632 |
| 15 | Sep 2041 | £57,652 | £0 | £82 |
| 16 | Sep 2042 | £48,810 | £0 | £0 |
| 17 | Sep 2043 | £39,562 | £0 | £0 |
| 18 | Sep 2044 | £29,889 | £0 | £0 |
| 19 | Sep 2045 | £19,772 | £0 | £0 |
| 20 | Sep 2046 | £9,190 | £0 | £0 |
| 21 | Jul 2047 | £0 | £0 | £0 |
This calculator does not account for lender terms, fees or early repayment charges.
Overpaying beyond that allowance can trigger an Early Repayment Charge (ERC). This can significantly reduce or even eliminate the interest savings from overpaying.
- Results are estimates only and do not constitute financial advice. Actual mortgage terms and savings will vary.
- Calculator inputs are processed in real time and are not stored. The one exception is the optional email report: if you choose it and send us your email address, that address and the four figures it uses are kept for up to 30 days.
- Your home may be repossessed if you do not keep up repayments on your mortgage.
The Advanced Mortgage Planner, a separate paid tool, can model what happens when your fixed rate ends.The Advanced Mortgage Planner, a separate paid tool, can model up to 5 lump sums and compare up to 3 plans. See a worked example
Email me this report (optional)
The free calculator shows how a monthly overpayment and one lump sum could change your mortgage.
The Advanced Mortgage Planner adds:
- Model what happens when your fixed rate ends, using the new rate you enter
- Add up to 5 lump sums, each in the month you choose
- Compare up to 3 overpayment plans side by side
- Check every mortgage year of each plan against a typical 10% allowance
- See a year-by-year schedule with annual and running totals
- Compare your plans on a balance chart, with interest vs principal and the home stretch for each plan
Your Full Mortgage Picture - In One Place
See a worked example of everything the planner shows, using fixed example figures.
When your fixed rate ends
The planner works out your new payment when your fixed rate ends, using the rate you enter, and keeps the shorter term your overpayments have earned.
Plans side by side
Compare up to 3 plans, each with a monthly overpayment and up to 5 lump sums, against making no overpayments.
Every mortgage year
See each year's balance, interest and principal with running totals, and a check against a typical 10% allowance for every year.
The planner uses the same calculations as the free calculator.
Advanced Mortgage Planner: £14.99 one-off payment, no subscription.
- The Advanced Mortgage Planner provides informational estimates only and does not guarantee savings or results.
Designed for UK mortgages. Estimates only. No advice provided.
Questions about overpayments or how this works?