Debt Payoff Calculator
See how long a balance takes to clear, what the interest costs, and exactly how much time and money an extra monthly payment would save.
Your debt
Works for a credit card, store card, or any balance with a fixed monthly payment.
Balance and rate
The amount you pay every month before any extra.
Anything you can add on top goes straight to principal.
Minimum payment vs. paying extra
An extra $150.00 a month clears the debt 1 year 10 months sooner.
Balance over time
How fast the debt actually disappears under each plan.
What this assumes
- A fixed interest rate and a fixed monthly payment.
- No new spending is added to the balance.
- Interest is charged monthly on the outstanding balance, then the payment is applied.
- Real card minimums fall as the balance does, which makes payoff far slower than a fixed payment.
Time until debt-free
2 years 1 month
Paying $400.00 a month, the balance clears in October 2028.
With your extra payment
- Total interest
- $1,812
- Total amount paid
- $9,812
- Debt-free date
- October 2028
What the extra payment buys
- Time saved
- 1 year 10 months
- Interest saved
- $1,713
- Without the extra payment$3,524 in interest
- 3 years 11 months
How credit card interest works
A card’s APR is an annual figure, but interest is charged monthly on what you owe. A 19.99% APR works out to about 1.67% a month. On a $8,000 balance that is roughly $133 in the first month alone.
Your payment covers that interest first. Only what is left reduces the balance. At $250 a month against $8,000 at 19.99%, the first payment retires about $117 of debt — and the balance takes 47 months to clear.
This is why minimum payments are so expensive. Minimums are typically set at 1%–3% of the balance, which is barely above the interest charge, so almost nothing goes to principal and the term stretches out for years.
Why an extra payment does so much
Extra money goes entirely to principal — none of it is absorbed by that month’s interest, which the base payment has already covered. Every dollar of principal removed also removes all the future interest that dollar would have accrued.
That is why the saving is so disproportionate. Adding $150 a month to a $250 payment on $8,000 at 19.99% cuts the payoff from 47 months to about 24 and roughly halves the interest. The extra payment was 60% larger; the benefit was far more than 60%.
Snowball versus avalanche
With several debts, the order you attack them in changes the outcome. Two methods dominate the advice.
- Avalanche
- Pay minimums everywhere, then put every spare dollar against the highest interest rate. Mathematically optimal — it always costs the least in total interest.
- Snowball
- Pay minimums everywhere, then attack the smallest balance first. Costs slightly more in interest, but clears whole debts sooner, and research on real households suggests people stick with it more reliably.
When the payment is not enough
If your payment is smaller than the monthly interest charge, the balance grows no matter how long you pay. The calculator detects this and tells you the smallest payment that would actually make progress.
If you are close to that line, a balance transfer card with a 0% introductory period, a lower-rate personal loan, or a hardship arrangement with the issuer are all worth investigating. A non-profit credit counselling agency can negotiate reduced rates and is a very different proposition from a for-profit debt settlement company.
Frequently asked questions
It depends on the balance, the APR and how much above the interest charge you pay each month. A $8,000 balance at 19.99% APR with a $250 monthly payment takes about 47 months and costs roughly $3,700 in interest. Raising the payment to $400 clears it in about 24 months and cuts the interest to around $1,700.
More than the extra amount suggests, because every dollar of extra principal also removes all the future interest that dollar would have generated. On a $8,000 balance at 19.99%, adding $150 a month to a $250 payment saves roughly half the total interest and clears the debt around two years sooner.
The avalanche method — highest interest rate first — always costs less in total interest. The snowball method — smallest balance first — costs a little more but produces visible wins sooner, and studies of real repayment behavior suggest people are more likely to see it through. If the rates are close together, the snowball’s motivational edge often outweighs the small extra cost.
Minimum payments are typically 1%–3% of the balance, only slightly above the monthly interest charge, so very little goes to principal. A balance that could clear in two to three years can take a decade or more, at several times the interest cost. If the minimum is below the monthly interest, the balance grows even while you pay.
Build a small emergency buffer first — one month of expenses is a common starting point — so an unexpected bill does not go straight back onto the card. After that, high-interest debt above roughly 8%–10% is usually the better return: paying off a 20% APR balance is a guaranteed 20% return, which no investment reliably matches. Always contribute enough to capture a full employer 401(k) match, since that is an immediate 50%–100% return.
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