Mortgage Payoff Calculator

Where the money actually goes

On this profile, the first payment carries about $3,062 of interest, which is roughly 74% of the $4,154 going out that month. The remainder reduces the balance. That proportion is not fixed: as the principal falls, the interest charge falls with it, so an increasing share of every later payment does useful work. This is why the last six months of a payoff plan clear far more principal than the first six, and why stopping halfway costs more than the halfway point suggests.

Across the whole plan you repay $331,200 to clear $300,000: the principal plus $31,200 of interest. Put differently, every dollar borrowed costs 1.10 dollars by the time the balance reaches zero. That multiple is the number worth carrying into any decision about refinancing, consolidating, or simply deciding whether a purchase is worth putting on credit at all.

Why the order of payment matters here

This profile spans rates from 6.5% on the mortgage to 22.99% on the credit card, a spread of 16.5 points. The avalanche method attacks the credit card first because each dollar sent there stops the most expensive interest from accruing. Over the full plan that choice is worth $2,925 against the snowball order, which starts with the smallest balance instead.

Whether $2,925 justifies the harder route is a real question rather than a rhetorical one. The snowball method clears its first balance sooner, which removes a payment from the monthly list and gives visible proof that the plan works. Research on consumer debt repayment has repeatedly found that people who see an account close early are more likely to still be following the plan a year later. A method that costs $2,925 more but gets finished beats a cheaper method abandoned in month five.

What an extra payment is worth

The plan above assumes $758 a month beyond the minimums, which is what brings the timeline to 36 months. Extra payments are unusually effective because none of the money is absorbed by interest: the interest for the period has already been charged on the balance at the start of it, so anything above the minimum lands entirely on the principal, and reduces every future interest charge as well.

The corollary is that the timing within the plan matters. An extra $100 paid in the first month removes interest for every remaining month; the same $100 paid in the final month removes almost none. If a windfall arrives, applying it early is worth substantially more than spreading it out, even though the total amount is identical.

If the plan slips

Plans rarely fail because the arithmetic was wrong; they fail because a month goes badly and the whole thing is abandoned rather than paused. Missing one extra payment on this profile adds roughly a month to the timeline. Missing it and then reverting to minimums indefinitely is what turns a 36-month plan into a decade. The recovery move is to resume the following month at whatever amount is possible, even a reduced one.

Two things are worth protecting even at the cost of a slower payoff. The first is a small cash buffer: without one, the next unexpected expense goes back onto the card being paid down, which undoes several months of work in a single transaction. The second is any payment on a secured debt, where falling behind risks the asset itself rather than only the interest bill. Neither is visible in a payoff timeline, and both decide whether the timeline survives contact with an ordinary year.