Tool · Calculator
Debt Payoff Calculator
Work out how long it takes to clear a debt and the total interest you'll pay, from your balance, interest rate, and monthly payment. Australian dollars.
Provide your balance, interest rate, and monthly payment to see when you'll be debt-free and how much interest you'll pay along the way. Try nudging the monthly payment up to see how much faster the balance clears and how much interest you save.
Debt Payoff
See how long it takes to become debt-free based on your monthly payments.
Estimated time to payoff
41months
Monthly payment
$400
Total interest
$4,400
Total paid
$16,400
Increasing payments shortens your payoff timeline and reduces interest costs.
This is the calculator I use to sanity-check my own numbers. It gives estimates, not advice - what to do with the result is yours to work out.
Frequently asked questions
- How is a debt payoff timeline calculated?
- Each month, interest is added to your balance at the monthly rate (the annual rate divided by twelve), then your payment is subtracted. Whatever is left over reduces the principal. The calculator repeats this month by month until the balance reaches zero, which gives both the payoff date and the total interest paid along the way.
- Why does paying a bit more each month help so much?
- Because every extra dollar goes straight to principal, and reducing the principal cuts the interest charged in every future month. On a high-rate debt like a credit card, even a small increase to the monthly payment can shave months or years off the timeline and save a large amount of interest, since you stop the balance from compounding against you.
- What if my payment is lower than the monthly interest?
- Then the debt never gets paid off - it grows. If your payment doesn't at least cover the interest charged that month, the balance increases instead of falling, and the calculator can't return a payoff date. This is the trap with making only the minimum payment on a high-interest card. The fix is to pay more than the monthly interest so the principal actually starts to fall.
- Should I pay off debt or save first?
- A common approach is to keep a small starter emergency fund, then throw everything at high-interest debt, because few investments reliably beat the rate on a credit card. Once expensive debt is gone, the focus usually shifts back to building savings and investing. The right balance is personal, and this calculator is here to show the cost of the debt, not to give advice.