Two methods, one honest comparison
There are two well-known ways to clear multiple debts. The snowball method pays the smallest balance first, regardless of interest rate. The avalanche method pays the highest interest rate first, regardless of balance.
Avalanche is always cheaper in pure arithmetic. Snowball clears individual debts sooner, which many people find easier to sustain. Most articles argue for one and quietly ignore the other. We would rather show you both numbers and let you decide, because the cheapest plan is worthless if you abandon it in month four.
What the calculator does
You enter each debt with its balance, interest rate and minimum payment, plus whatever you can afford to pay in total each month. It projects both strategies side by side: how long each takes, how much interest each costs, and the order debts get cleared in.
The difference between the two is often smaller than people expect. Seeing that difference in actual pounds is usually more useful than being told which method is theoretically superior.
What we deliberately do not do
We do not sell debt consolidation, we are not paid referral commission, and we do not recommend any lender or debt management company. The calculator has no product to steer you toward. That is deliberate, because this is an area where a great deal of online content exists mainly to generate leads.
Who publishes this site
SnowballCalc is built and maintained by CJ Software Ltd, a UK software company that develops a small family of free, single-purpose calculators. We are a software business, not a debt advice service, and we say so plainly because it matters when you decide how much weight to give a number on a screen.
The site is funded by advertising. Advertisers have no influence over the calculations, the guidance, or what we choose to write about.
If you are struggling, please read this
This calculator assumes you can meet all your minimum payments and have something left over. If that is not your situation, a repayment strategy is not the tool you need, and free expert help exists.
StepChange, National Debtline and Citizens Advice all provide free, confidential and impartial debt advice in the UK. None of them charge, and none of them will sell you a product. If you are behind on priority bills such as rent, mortgage, council tax or energy, contact one of them before doing anything else. Those debts have consequences that a spreadsheet cannot capture.