Extra Loan Payments: Calculate the Interest and Time Actually Saved
Extra principal can remove future interest, but the saving depends on timing, remaining rate, and whether the payment reduces principal instead of advancing the due date.
Loan Early Payoff Calculator
Measure interest saved and months removed without treating a future payment as guaranteed.
Calculations stay in this browser. No entries are saved.
Compress the remaining payment schedule
Extra principal reduces the balance that creates future interest. The result shows both time removed and interest avoided.
- Start from today's payoff
- Apply lump sum or monthly extra
- Measure the shorter schedule
Interest saved and new payoff date
Calculated resultNot available
Confirm principal-only application, payment posting and any prepayment charge.
How extra principal changes the schedule
The scheduled path uses the current balance, rate and remaining term. The accelerated path reduces principal by the entered lump sum, then applies the scheduled payment plus the recurring extra amount until payoff.
Prepayment details to confirm first
Confirm principal-only allocation, posting dates and prepayment charges. Preserve enough liquid savings for emergencies.
This calculator supports The Real Cost of Borrowing. Extra Loan Payments: Calculate the Interest and Time Actually Saved explains which details can change the inputs. The calculation methodology shows how we handle timing, rounding and exclusions.
Evidence standard for this calculation
Confirm principal-only application, payment posting and any prepayment charge. Inputs remain in the browser and outputs are rounded for display.
Read the complete methodology →Questions about paying a loan off early
How many months can extra principal remove?
The result compares the scheduled payoff date with a path that immediately reduces principal and applies the recurring extra amount each month.
How much scheduled interest may be avoided?
Interest avoided is the scheduled interest that no longer accrues after faster principal reduction, before any prepayment fee.
Servicer rules to confirm before paying extra
- Principal-only allocation and payment posting
- Prepayment penalties and fee refunds
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Loan Total Cost Calculator →
Separate the advertised rate from the dollars that leave your account.