See how long it takes to pay off a debt at a fixed monthly payment, and how much total interest you will pay.
With multiple debts, paying the highest-rate one first (avalanche) saves the most interest. Paying the smallest balance first (snowball) builds momentum through quick wins.
Minimum payments on high-rate debt can take decades. Even small increases dramatically cut both time and total interest.
Paying off debt is one of the highest-return moves in personal finance. Eliminating a balance charging 20% interest is effectively a guaranteed 20% return — something no investment can promise. This calculator shows how long it will take to clear your debt and how much interest you will pay, and how dramatically extra payments shorten both.
The two variables you control are how much you pay each month and how you order multiple debts. Small increases to your monthly payment have an outsized effect, because every extra dollar goes straight to principal and skips all the future interest it would have generated.
Each month, interest is charged on your remaining balance, and whatever you pay above that interest reduces the principal. The calculator steps through month by month until the balance reaches zero, tracking total interest along the way:
monthly interest = balance × (APR ÷ 12); principal paid = payment − interest
A $10,000 balance at 20% APR, comparing two monthly payments:
| Monthly payment | Time to pay off | Total interest |
|---|---|---|
| $250 | ~5 yr 8 mo | ~$6,900 |
| $400 | ~2 yr 8 mo | ~$2,700 |
Adding $150 a month cuts the payoff time by three years and saves over $4,000 in interest. High-interest debt rewards aggressive payment more than almost anything else you can do with money.
Pay minimums on everything, then throw every extra dollar at the debt with the highest interest rate. Mathematically optimal — it minimizes total interest paid. Best if you are motivated by numbers.
Pay minimums on everything, then attack the smallest balance first. You clear individual debts quickly, and the psychological momentum keeps many people going. It costs slightly more in interest but has a strong behavioral track record.
The best strategy is the one you will actually stick with. If motivation is your challenge, the snowball's quick wins may beat the avalanche's math.
Estimates are for educational purposes only and are not financial advice. Actual terms vary by lender.