When extra mortgage payments matter most
Extra principal can have its biggest impact when the remaining balance is high and many years of interest are still ahead.
That is why payoff examples can be useful even before deciding whether to recast, refinance, or simply keep the existing loan.
How the extra payment and term shape this example
An extra payment in this range is usually large enough to move the payoff date by a year or more without straining the household budget.
A 20-year baseline sits between the two extremes, so the dollar impact of extra payments here is typically more than a 15-year loan but less than a 30-year loan.