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    Mortgages / United Kingdom

    UK Mortgage Calculator

    A UK repayment mortgage with a product fee, showing the true cost including the fee and the effect of a longer term. UK terms are often 25 to 40 years, which lowers the payment and raises the interest sharply.

    Monthly payment$1,425Total interest$177,588Fee added to loan$5.70
    Monthly payment
    $1,425
    25 years
    Total interest
    $177,588
    Over the term
    Fee added to loan
    $5.70
    Per month
    True cost
    $428,587
    Interest plus fee
    Term comparison
    The product fee is added to the loan or paid up front; both are shown.
    Term comparison
    TermPaymentTotal interest
    15 yr$1,945$100,024
    20 yr$1,616$137,734
    25 yr$1,425$177,588
    30 yr$1,304$219,483
    35 yr$1,222$263,300
    Inspect the model
    Choose a quick result view, a scaled comparison, or the complete diagnostic set.
    Total interest against term
    The last five years of a 30-year term cost more than the first ten.
    Total interest against term0.0005.898e+41.180e+51.769e+52.359e+52.949e+515 yr15 yr20 yr20 yr25 yr25 yr30 yr30 yr35 yr35 yrUK Mortgage Calculator
    Canonical equations
    The exact relationships implemented by this engine.

    M = P·i/(1 − (1+i)^−n) · Repayment mortgage.

    M·n + fee · Fee included.

    finance methodology

    A clear path from inputs to results.

    A UK repayment mortgage with a product fee, showing the true cost including the fee and the effect of a longer term. UK terms are often 25 to 40 years, which lowers the payment and raises the interest sharply.

    Step-by-step methodWorked exampleAssumptions explained

    How to use

    1. Set loan (£).
    2. Set rate (%).
    3. Set term (years).
    4. Set product fee (£).
    5. Read the headline metrics, then check the table for the detail.

    The formula

    M=P⋅i/(1−(1+i)−n)M = P·i/(1 − (1+i)^−n)

    Reference: Repayment mortgage with a product fee (Broverman, Mathematics of Investment and Credit).

    Worked example

    At the default inputs

    Inputs
    • Loan (£): 250000; Rate (%): 4.75; Term (years): 25; Product fee (£): 999
    Calculation path
    1. 1

      Monthly payment: $1,425 · Total interest: $177,588 · Fee added to loan: $5.70 · True cost: $428,587

    Result

    Monthly payment: $1,425 · Total interest: $177,588 · Fee added to loan: $5.70

    Interpreting the result

    A £2.500e+5 repayment mortgage at 4.75% over 25 years is $1,425 a month.

    Assumptions & limitations

    • Fixed rate for the whole term.
    • No early repayment charge.

    Frequently asked questions

    What is a product fee?

    A fixed charge for the rate, added to the loan or paid up front.

    Why do UK terms run to 40 years?

    Longer terms lower the payment but raise the total interest sharply.

    Methodology last reviewed 2026-10-22. Results are informational and not financial or engineering advice — see our disclaimer.