Debt Avalanche Calculator

This calculator applies the debt avalanche method to your debts in New Zealand, the payoff strategy that clears them with the least total interest. The idea is simple and ruthless: you pay the minimum on every debt to keep them all in order, then throw every spare dollar at the single debt charging the highest interest rate. Once that one is gone, you roll the whole payment, its old minimum plus your extra, onto the next-highest rate, and so on down the line, so the payment snowballs in size even as it targets the most expensive debt first. Because the highest-rate debt is doing the most damage, killing it first saves more interest than any other order. You enter up to three debts with their balance, interest rate and minimum payment, plus the extra amount you can put toward debt each month, and the calculator simulates the payoff month by month and shows how long until you are debt-free and the total interest you will pay along the way. Compare it with the snowball method, which targets the smallest balance first for motivation, to see the trade-off between maths and momentum. The key is to keep paying the same total every month and not take on new debt. Estimate only, not financial advice.

Pays minimums on all debts, then all spare cash to the highest rate, rolling freed-up payments onward. Keep the total payment constant. Estimate only.