Remortgage Lab

Fixed rate ending calculator

Last checked UK · illustrative onlyNot a lender or brokerAboutDisclaimer

Published by Rodway Labs — not a mortgage adviser

See what your monthly mortgage payment becomes when your fixed rate ends: on a new deal, and on your lender’s standard variable rate (SVR) if no new deal is in place. Starter figures are the site example, not market rates.

Equations and method

Your inputs

Starter figures are UK example values you can edit. Scenario rates, not a market quote. 4.19%, 4.39%, 4.14% and 7.49% SVR on this site are fixed example figures, used so every page shows the same sums. They are not current market rates, which may be higher or lower. Enter the rates from your own offer. Results update as you type.

Results

On these inputs, the monthly payment rises by about £20 when the fix ends and the new deal starts. This is arithmetic on the figures entered, not a recommendation.

Monthly payment now

At your current fixed rate

£1,073.81

Monthly payment on the new deal

£1,093.98

Change each month

New deal compared with now

£20.17 more

Change over a year

Twelve monthly payments

£242 more

Monthly payment on the SVR

If no new deal is in place when the fix ends

£1,431.68

SVR compared with the new deal

For each month spent on the SVR

£337.70 more

Method: the standard capital-and-interest formula on the same balance over 264 months, at each of the three rates. Fees and any early repayment charge are not included.

Illustrative only — not personalised advice, not a credit or mortgage offer, and not an FCA-regulated recommendation. Your offer and ESIS set the real ERC, fees and terms. Full calculator disclaimer.

What to do next

Assumptions

  • Example starters: £185,000, 22 years left, 4.19% now, 4.39% new deal, 7.49% SVR. Fixed example rates, not current market rates.
  • Capital and interest repayment, with the same balance and remaining term on every line.
  • Each rate is held constant. Product fees, legal fees, cashback and any early repayment charge are left out.

How to use this calculator

  1. Enter the balance you expect to owe on the day your fixed rate ends, and the years left on the mortgage.
  2. Enter your current fixed rate from your offer or latest statement.
  3. Enter the rate on the new deal you have been quoted, either a product transfer with your lender or a deal with a new lender.
  4. Enter your lender's standard variable rate, which it publishes on its website and states in your offer.
  5. Read the payment on the new deal and the change each month. The SVR lines show what each month without a new deal would cost.
Equations

M = P × r(1+r)ⁿ / ((1+r)ⁿ − 1), where P is the balance, r is the monthly interest rate (annual ÷ 12 ÷ 100), and n is the number of months left. The same balance and term are used at the current rate, the new deal rate and the SVR, and the payments are compared.

The assumptions are listed in the box under the results.

How this calculator works

Short answer: this shows the monthly payment after your fixed rate ends. Use it when you have a quote for a new deal, or want to see what the lender’s standard variable rate (SVR) would cost if nothing is arranged in time.

  1. The balance and the years left stay the same on every line. Only the interest rate changes.
  2. The monthly payment is worked out three times with the standard repayment formula: at your current fixed rate, at the new deal rate and at the SVR.
  3. Change each month = payment on the new deal − payment now. Change over a year is that figure × 12.
  4. SVR compared with the new deal = payment on the SVR − payment on the new deal, for each month spent on the SVR.

These steps match the code behind the tool. The equations are in the box above, and the full method is on the calculator methodology page.

Worked example

Scenario rates, not a market quote

Shared example house. Fixed example rates, not current market rates: £185,000 with 22 years left, 4.19% now, a new deal at 4.39% and an SVR of 7.49%.

The payment is £1,073.81 now and £1,093.98 on the new deal, which is £20.17 more each month, or about £242 over a year.

On the SVR the payment is £1,431.68, about £338 a month more than the new deal. Two months on the SVR while a new deal completes would cost about £675 more in payments than the new deal would have.

Limitations: what this ignores

  • Product, legal, valuation and broker fees, and cashback. The true cost calculator adds those.
  • Any early repayment charge for leaving before the fix ends.
  • Interest-only and part-and-part mortgages.
  • Rate changes after the new deal starts, and changes to the SVR.
  • A different term or extra borrowing on the new deal.

Sources

Guides that go with this tool

Questions

Which balance should I enter?
The balance you expect to owe when the fix ends. Your statement or online account shows today’s balance. On a repayment mortgage it will be a little lower by the end date.
What rate should I use for the new deal?
The rate on a written quote or illustration, for a product transfer or for a new lender. The starter rate is a fixed example, not a market rate.
What is the SVR line for?
It shows the payment if no new deal is in place when the fix ends and the mortgage moves to the lender’s standard variable rate. Use your own lender’s published SVR.
Does this include fees or an early repayment charge?
No. It compares monthly payments only. Use the true cost calculator to add fees, cashback and any charge.
Will my lender’s figure match?
It should be close on a repayment mortgage. Lenders can differ slightly through day-count rules, rounding and any fees added to the loan.

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