Principal Curtailment Calculator

Test lump sums and recurring extras quickly. See payoff date shifts and total interest instantly. Use the schedule to decide if curtailment makes sense.

Calculator

Enter loan details and optional curtailments. Results appear above after you calculate.
Starting principal balance.
Nominal APR, compounded per period.
Used to estimate the base number of payments.
Affects interest per period and schedule dates.
Dates use this as payment #1.
Payment settings
Auto payment uses the standard amortization formula.
Override the calculated payment amount.