How to use the debt payoff calculator
- Enter the balance and APR.
- Enter your planned monthly payment.
- Add an extra payment to compare plans side by side.
The formula
Each month: Balance = Balance × (1 + APR/12) − Payment
If the payment is less than the monthly interest, the balance grows — the calculator warns you.
Worked example
An 8,500 balance at 21.9% APR with 300 a month takes about 3½ years. Adding 100 a month cuts more than a year and saves a meaningful amount of interest.
Tips from the numbers
- Avalanche: pay extra on the highest APR first — saves the most money.
- Snowball: clear the smallest balance first — builds momentum.
- Ask your lender for a lower rate; a balance transfer or consolidation loan can help if fees are low.
- Stop adding new charges while you pay down.
Watch: learn the concept
Frequently asked questions
Avalanche or snowball?
Avalanche minimizes interest; snowball maximizes motivation. The best method is the one you'll stick to.
Is the minimum payment enough?
Minimum payments are designed to keep you in debt for years. Pay as much above the minimum as you can.
Should I save or pay off debt first?
Many people build a small emergency buffer first, then attack high-interest debt.
Want a second opinion? Our free review connects you with a vetted professional for your situation. Get matched →