£100,000 mortgage: monthly payments

By The PocketSums team. Updated 30 September 2026. How we calculate

Borrowing £100,000? At 4.5% over 25 years you would pay £555.83 a month. Every rate and term is compared below.

At 4.5% over 25 years
£556 a month
Total interest
£66,749
Income needed (4.5x)
£22,222
Overpay £50 a month
save £10,570
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Monthly payment£555.83a month

Borrowing £100,000 (91% loan to value). Total repaid £166,749, of which £66,749 is interest.

A £100,000 repayment mortgage at 4.5% over 25 years costs £555.83 a month. You would repay £166,749 in total, of which £66,749 is interest.

Monthly payments on £100,000 by rate and term

Rate 20 years 25 years 30 years 35 years
3.5% £580 £501 £449 £413
4% £606 £528 £477 £443
4.5% £633 £556 £507 £473
5% £660 £585 £537 £505
5.5% £688 £614 £568 £537
6% £716 £644 £600 £570

How £100,000 is paid off over 25 years

£0k£50k£100k0y5y10y15y20y25y
  • Balance still owed
  • Interest paid so far
At 4.5%. Interest is heaviest in the early years, when the balance is highest.

Total interest on £100,000 by term

  1. 20 years£51,836 (£633 a month)
  2. 25 years£66,749 (£556 a month)
  3. 30 years£82,408 (£507 a month)
  4. 35 years£98,769 (£473 a month)

A longer term lowers the monthly payment but adds interest. Stretching from 25 to 35 years saves £83 a month and costs £32,020 more overall.

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Questions people ask

What are the monthly payments on a £100,000 mortgage?

£555.83 a month on a 25 year repayment mortgage at 4.5%. At 4% it is £527.84 and at 5% it is £584.59. Interest only at 4.5% would be £375.00.

What salary do I need for a £100,000 mortgage?

At the usual 4.5 times income, about £22,222 for a single buyer or a joint household income. Some lenders go to 5 or 5.5 times, which would need around £18,182.

How much does overpaying a £100,000 mortgage save?

Paying £50 extra a month at 4.5% clears it about 3 years 6 months early and saves roughly £10,570 in interest. Check your lender's overpayment limit, often 10% a year on fixed deals.