Find out how much an extra monthly payment saves you in time and interest.
Current outstanding loan balance.
Annual interest rate on the loan.
Original term in years for the baseline schedule.
Additional amount paid toward principal each month.
When extra payments begin — affects the new payoff date.
Months Saved
108
Months shaved off the original payoff schedule by the extra payments.
Interest Saved
$79,800.51
Total interest not paid because principal amortizes faster.
Standard Payment
$1,199.10
Baseline monthly payment before the extra.
Payoff in
252 months
New shortened payoff horizon in months.
Estimated Payoff
January 2047
Interest Without Extras
$231,676.38
What this means
Shows the outsized payoff from even small, consistent extra principal payments due to compounding in reverse.
Extra principal payments give an outsized payoff: every dollar you prepay stops future interest from accruing. This tool simulates the full amortization with and without a recurring extra payment.
Formula
interest saved = total interest (standard) − total interest (with extra principal)
Worked examples
FAQ
Is an extra payment always worth it?
Usually for high-rate debt, but weigh higher-return investments and liquidity needs. Also confirm your lender applies the extra amount to principal.
What if I can only pay extra occasionally?
Any extra principal reduces total interest. A recurring monthly amount produces the largest, easiest-to-plan saving.
Important assumptions