Excel mortgage calculator with extra payments: how to get payoff date without full amortization table?
Here are some formula to help you:
- yearly rate, principal, original term: input parameters
- original term (in months):
= B4 * 12 - original monthly payback amount:
=PMT(B2/12,B4*12,B3) - extra payment starting from Nth month: input
- balance before first extra payment:
=-FV(B2/12,B8-1,B6,B3) - new total term in months:
=NPER(B2/12,B6+B7,B9)+B8-1
