Debt payoff toolkit
This extra payment savings calculator compares your current payoff timeline against adding extra each month: interest saved and years cut, side by side. Small habit, enormous math.
Estimates only. Not financial advice. This calculator runs entirely in your browser and nothing you type leaves your device.
Your regular payment mostly services interest early on. Extra money skips the line: every extra dollar goes straight to principal, and each principal dollar destroyed also destroys all the future interest it would have earned the lender. That double effect is why the savings curve is so steep. This extra payment savings calculator shows both timelines, current payment alone versus payment plus extra, so the value of the habit is concrete, not motivational poster talk.
The numbers above: $12,000 at 21.99%, $300 a month, plus $150 extra. Current path: 6 years and 1 month, $9,816.14 in interest. With the extra: 3 years and 1 month, $4,621.65 in interest. You save $5,194.49 and three full years. The extra $150 a month totals $5,550 over the payoff, and it buys back $5,194.49 of interest plus 36 months of freedom. Almost a one to one trade of dollars for dollars, plus the time.
The best extra payment is the one you never decide to make. Set the higher amount as autopay and treat it as the real minimum. If income varies, set autopay at the base and manually add extra in good months. And target it: run all your debts through the debt snowball calculator so the extra always attacks the right balance first.
Enter your balance, APR, current payment and the extra amount you would add each month. It amortizes both timelines, the current payment alone and the payment plus extra, then reports the interest saved and how much sooner you are debt free, including the new debt free date.
More than intuition suggests, because extra payments attack principal directly and every principal dollar kills its future interest. On the example above, $150 extra saves $5,194.49 and three full years. Run your own numbers: the curve is steepest at the start.
One debt. Minimums everywhere, then the entire extra at a single target until it dies. Spreading extra across debts dilutes the compounding effect. Our debt snowball calculator automates the targeting across up to four debts.
Monthly wins slightly: money hits principal sooner, so less interest accrues. But the difference is small next to the decision to pay extra at all. Pick whichever you will actually sustain.
Irregular extra payments still help enormously. This extra payment savings calculator assumes a steady extra, which understates lumpy payers slightly and overstates them slightly in bad months. The direction is what matters: extra principal, whenever it lands, shortens the timeline.