Prepayment repayment

Compare multiple prepayments using either term reduction or lower payment mode.

If calculation UI does not appear, reload with JavaScript enabled. Related context links below remain available.

Calculation specification

Reviewed on:

Formula basis

Each prepayment is deducted immediately after the scheduled payment at its payment index. Term reduction retains the payment target; payment reduction recomputes PMT from the new balance over the remaining periods.

Calculation method

Adds one or more prepayments to the ordinary amortization schedule and compares interest and payoff timing under term-reduction or payment-reduction treatment.

Exclusions and checks required

  • Prepayment fees, minimum amounts, acceptance dates, and lender-specific recalculation rules are excluded.
  • Each event is identified by payment number and cannot represent a payment on an exact date or before the scheduled installment.

Example input:：Prepaying JPY 1 million after years 5 and 10

principalMan
3000
method
annuity
rounding
floor
frequency
monthly
initialRate
1.5
initialYears
35
laterRate
1.5
termYears
35
termMonths
0
startMonth
2026-07
prepayments
60,100 120,100
prepaymentStrategy
reduceTerm

Interest savings are the difference from this calculator's no-prepayment baseline, not a contractual settlement quote.

FAQ

Who is this calculator for? Prepayment repayment

Compare multiple prepayments using either term reduction or lower payment mode.

What values should I enter?

Applies to: Loan repayment / Term-reduction keeps regular payment unchanged; lower-payment keeps remaining periods unchanged.

How should I interpret this estimate?

Adds one or more prepayments to the ordinary amortization schedule and compares interest and payoff timing under term-reduction or payment-reduction treatment.

How to use

  1. Enter your input values and press Calculate.
  2. Review the result and compare it with expected context.
  3. Each prepayment is deducted immediately after the scheduled payment at its payment index. Term reduction retains the payment target; payment reduction recomputes PMT from the new balance over the remaining periods.