Skip to content
CalcTortoise

Remortgage Calculator

Compare your current mortgage with a new deal. See the monthly saving, how long the switching fees take to pay back and the saving over the life of the loan.

Written by the CalcTortoise editorial team · How we work

Current loan

years

New loan

years
Assumed: $2,000 closing costs. Change

Pay the costs

Saving so far, year by year

YearSaving so far (after costs)
Year 1-$306
Year 2$1,388
Year 3$3,082
Year 4$4,776
Year 5$6,469
Year 6$8,163
Year 7$9,857
Year 8$11,551
Year 9$13,245
Year 10$14,939
Year 11$16,633
Year 12$18,327
Year 13$20,021
Year 14$21,714
Year 15$23,408
Year 16$25,102
Year 17$26,796
Year 18$28,490
Year 19$30,184
Year 20$31,878
Year 21$33,572
Year 22$35,266

How to use this calculator

  1. Enter your current balance, rate and the years left.
  2. Enter the new rate, the new term and the switching fees.
  3. Choose whether to pay the fees upfront or add them to the loan.

Frequently asked questions

Is it worth remortgaging?

When the saving repays the switching fees well before you move or switch again. In the example ($250,000 at 5.5% moved to 4.5% with $2,000 of fees), you save $141 a month and recover the fees in 1 year 3 months.

Should I extend the term when I remortgage?

It lowers the payment but usually raises the total cost. Stretching the example to 30 years gives a lifetime saving of -$26,476, against $35,266 on the same term.

Should fees be added to the loan?

Adding them avoids paying upfront, but you then pay interest on the fees for the whole term. Paying them upfront costs less overall.

What about early repayment charges?

If your current deal charges a fee for leaving early, add it to the switching fees so the comparison is fair.

Sources and method

Standard compound-interest formulas, tested against worked examples. Nothing here depends on outside data; the rates you type in are your own assumptions.

No outside data is used. The numbers you type in are the only inputs.

Page and formula last reviewed . How we calculate · Editorial policy · Corrections and change log

Last updated 10 October 2026. For information only — not financial advice. Check the final figures with your lender or bank.