Debt Paydown Calculator
Find the month your loan or card will finally be gone, or see what an extra payment buys you. This is the same projection engine that powers liability forecasts inside the WealthTrunk app.
For illustrative purposes only. Not financial, tax, or investment advice.
Anything above your required payment. The dashed line shows where you'd be without it.
Debt is only half the picture. WealthTrunk tracks what you owe alongside what you own, projects both forward, and shows your real net worth in one place.
Try the appHow this calculator works
Interest is charged monthly
Your APR is converted to a monthly rate — (1 + rate)1/12 − 1 — and applied to whatever is still outstanding. As the balance falls, so does the interest, which is why the curve steepens as it approaches zero.
Your payment lands after the interest
Each month's interest is added first, then your payment comes off the total. Whatever is left over after covering the interest is the only part that actually reduces the debt.
Extra payments compound in reverse
Every extra dollar goes straight at the principal and stops earning the lender interest for the rest of the loan. Add even a small amount and watch both the payoff date and the interest total move.
The interest total is the real price
The stat cards separate what you borrowed from what the debt costs you on top. On a long loan at a high rate, the interest can rival the balance itself.
Debt paydown calculator FAQ
How is the payoff date calculated?
Month by month. Each month interest is added to the balance at one month's worth of your APR — (1 + rate)^(1/12) − 1 — and then your payment is subtracted. The loan is paid off the first month the balance reaches zero. That's the same order the WealthTrunk app uses for liability accounts, so the projection here matches what you'll see in the app for the same inputs.
Why does a small extra payment save so much?
Every extra dollar comes off the principal, and that dollar stops accruing interest for the entire remaining life of the loan. Early payments have the longest time to work, which is why an extra amount that looks trivial next to the balance can cut years off the term.
What does "Never" mean in the result?
Your payment is smaller than the interest charged in the first month, so the balance grows instead of shrinking and the loan is never retired. The note under the chart shows the monthly amount you'd need just to cover the interest.
Are these results adjusted for inflation?
No, and deliberately so. A debt is a fixed nominal obligation — the payment you owe doesn't shrink because prices rose. Every figure here is in today's dollars at face value, which is what you'll actually write checks for. That's the opposite convention from our investment calculator, where inflation matters to what a balance can buy.
Does this handle credit cards with a minimum payment?
Partly. It models a fixed monthly payment, which is what most people actually set up. A credit card's true minimum shrinks as the balance falls, which stretches payoff much further than a fixed payment of the same starting size. Enter what you genuinely pay each month rather than the card's stated minimum.
Keep going
Become A Financial Maximizer
Start tracking your net worth today. See where you stand and where you're headed.
Downloadon the App StoreFree to download. No account required.