How the debt snowball method works

The debt snowball is a repayment strategy with one simple rule: pay the minimum on every debt, then throw every spare pound, dollar or euro at one debt at a time. When that debt is cleared, its monthly minimum payment doesn't go back into your pocket — it rolls onto the next debt, on top of the extra you were already paying. Each payoff makes the payment attacking the next debt bigger, like a snowball gathering size as it rolls downhill.

In the classic snowball you order debts from smallest balance to largest. The quick early wins are the point: clearing a debt in a few months proves the plan works and frees up a minimum payment fast. The main alternative, the avalanche method, orders debts by highest interest rate first. It's mathematically cheaper, but the difference is often smaller than people expect — and a plan you stick to beats a plan you abandon.

What this planner does differently

Most snowball calculators assume your income never changes. Over a multi-year payoff that's rarely true. This planner lets you model annual pay rises — both inflation-style percentage rises and one-off band or promotion increases, applied in the month each earner actually gets them. It supports multiple earners, either as salary minus personal expenses or as a simple "free money" figure.

You choose what percentage of your leftover money goes to debt, drag your debts into any order — or press one button to test every possible payoff order and apply the best one. A built-in avalanche-vs-snowball comparison shows what each strategy would cost in interest and time, so you can pick early wins or maximum savings with your eyes open.

It also handles the things real payoffs throw at you: one-off lump sums (a bonus, tax refund or gift aimed at a chosen month), scheduled rate or payment changes on a debt — such as a 0% promotional rate ending or a minimum stepping up — and an optional emergency fund to build from spare money before overpaying. A "what if I paid a bit more each month?" slider previews how much sooner you'd be debt-free.

The planner then shows your debt-free date, total interest paid, a milestone breakdown each time a debt clears (including exactly how big your snowball has grown), and charts of balances, payments and the free money waiting for you after debt. You can track your real progress by logging actual balances over time to see whether you're ahead of or behind plan, switch between eight currencies, collapse or reorder any section, and export everything to CSV or a multi-page PDF, share a link, or install it as an app that works offline.

Is my data private?

Yes. Everything you type stays in your own browser. There are no accounts, no server, and nothing is uploaded. See the privacy policy for details.

A note of caution

This tool is for planning and education — it isn't financial advice. Interest is modelled as monthly compounding at APR÷12, which is a good approximation but won't match every lender's statement to the penny. If you're struggling with debt, free debt advice services (such as StepChange or National Debtline in the UK) can help with options a calculator can't, like negotiating with creditors.