Extra Payment Calculator

Find out how extra payments change your loan payoff time and interest.

Loan amount ($)

Interest rate (%/yr)

Amortization (years)

Payment frequency

Start date (MM / YY) (optional)

Extra payment type

Extra amount ($)

Lump sum date (MM / YY) (for one-time)

Extra payment end (MM / YY, optional)

Autosaved locally

Results

Regular payment

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Total interest (baseline)

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Total paid (baseline)

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Payoff time (baseline)

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Payoff date (baseline)

—

Total interest (new)

—

Total paid (new)

—

Payoff time (new)

—

Payoff date (new)

—

Interest saved

—

Time saved

—

What this calculator does

This calculator shows how extra payments toward principal change your payoff date and total interest on a loan.

How the calculation works

Regular payments use standard amortization for the chosen frequency. Extra payments are applied to principal after scheduled interest/principal for each period. Lump sums are clamped so the balance never goes negative.

Results shown

Baseline payoff time and totals, plus the new payoff date/time, interest saved, time saved, total paid with extras, and total extra paid. If no start date is provided, payoff date is shown as “—”.