MoneyInJapan

Early-repayment calculator

Extra payment, term vs payment reduction, interest saved, and liquidity sacrificed.

Direct answers

Enter an extra payment to see the interest saved and term shortened under term-reduction versus payment-reduction, alongside the liquidity you sacrifice and the break-even return.

Key points

  • Compares term reduction and payment reduction.
  • Shows interest saved, term shortened, and liquidity sacrificed.
  • Considers the mortgage-tax deduction you may forgo.
  • Term reduction usually saves more interest, all else equal.

Inputs and outputs

Inputs: current balance, rate, remaining term, extra payment, fee, method (term or payment reduction), emergency-fund yield, and mortgage-tax deduction.

Outputs: interest saved, term shortened, liquidity sacrificed, and the break-even return your cash would need to beat the prepayment.

How to interpret the result

Preserve emergency liquidity before prepaying; the tool shows the deduction you may lose and the return your cash would need to make prepayment the wrong choice.

What the tool shows — and what it doesn’t

In short: Compares term reduction and payment reduction; Shows interest saved, term shortened, and liquidity sacrificed; Considers the mortgage-tax deduction you may forgo; Term reduction usually saves more interest, all else equal.

A calculator is only as good as its inputs and the scenarios you test, and it models arithmetic, not approval: it cannot tell you whether a lender will lend, what rate underwriting will actually offer, or how your circumstances will change. Use it to compare options and to stress-test — run a mortgage at the offered rate plus one, two, and three points, and a purchase at pessimistic as well as central assumptions — rather than to produce a single answer. Advertised rates are execution-month or example figures, not guaranteed offers, so treat any result as a planning estimate and confirm the real numbers with a dated written quotation before you commit.

Key points to carry away: Compares term reduction and payment reduction; Shows interest saved, term shortened, and liquidity sacrificed; Considers the mortgage-tax deduction you may forgo; Term reduction usually saves more interest, all else equal. Use the linked guides and calculators for the full decision, and confirm anything material with the lender, a licensed broker, a judicial scrivener, or a tax accountant before you act.

Who this is for

  • Buyers and borrowers modeling a decision
  • Anyone stress-testing affordability

What this is not

  • A guaranteed quote or approval
Important cautions
  • Preserve emergency liquidity before prepaying; the tool shows the deduction you may lose and the return your cash would need to make prepayment the wrong choice.

Frequently asked questions

Is early repayment always best?

No; liquidity, tax deductions, and alternative uses of cash matter.

Which saves more: term or payment reduction?

Term reduction usually saves more interest, all else equal.

Sources