Debt Payoff Calculator
Plan the snowball or avalanche method across all your debts and see which costs less
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
On top of the minimums. This is the money that does the real work.
Add a debt with a balance above zero to see a plan.
About this tool
When you owe money on several things at once, the order you clear them in changes both how long it takes and how much it costs. This calculator runs the two standard approaches across all your debts at the same time: the avalanche method, which attacks the highest interest rate first and always costs the least, and the snowball method, which clears the smallest balance first and gets a debt off the list soonest. It simulates every month properly, including the part most people miss - when a debt is cleared, its minimum payment rolls into the next one, which is what makes the later payoffs accelerate. You get the payoff order, the month you are debt free, and the exact interest difference between the two strategies, so the choice is yours to make with a number in front of you.
How to use this tool
- List every debtName, current balance, APR and the minimum you must pay each month. Include store cards and overdrafts, not just the obvious ones.
- Add your extra paymentAnything you can pay above the minimums. This is the money that actually shortens the plan.
- Compare the two strategiesSwitch between avalanche and snowball. The interest difference between them is shown directly.
- Check the payoff orderThe order each debt clears in, when, and how much interest each one cost you.
- Adjust until it is realisticRaise or lower the extra payment to find a plan you can actually stick to for the whole term.
Key features
- Runs both strategies at once, so you see the real cost difference instead of guessing.
- Correctly rolls a cleared debt minimum into the next debt - the effect that makes a snowball speed up.
- Handles any number of debts, at any mix of interest rates.
- Tells you plainly when the payments will never clear the balance, instead of showing an impossible date.
- Shows interest paid per debt, not just one lump total.
- Completely private and free - your balances stay in your browser.
Common uses
- Deciding whether to clear the small store card first or the expensive credit card.
- Seeing how much sooner you would be debt free if you found an extra 100 a month.
- Checking whether a consolidation offer actually beats your current plan.
- Setting a realistic debt-free date before committing to a budget.
- Showing a partner the concrete cost of one approach versus the other.
Tips for better results
- Avalanche always costs less in interest. Snowball works better for people who need an early win to stay motivated - both are valid.
- Always keep paying every minimum. Missing one adds fees and damages your credit, which costs far more than the interest saved.
- Put any windfall straight onto the target debt rather than spreading it across all of them.
- Re-run this whenever a rate changes, since a promotional 0% period ending can reorder the whole plan.
Mistakes to avoid
- Forgetting a debt. A single missing store card can make the whole plan wrong.
- Entering the monthly interest rate instead of the annual APR, which understates the cost by roughly twelve times.
- Assuming the minimum payment stays fixed. Many card minimums fall as the balance drops, which slows real-world payoff.
- Choosing snowball, seeing the extra cost, and feeling it was the wrong choice. If it is the plan you will actually finish, it is the better plan.
Frequently asked questions
Both pay every minimum and then throw all spare money at one debt. Avalanche targets the highest interest rate, which mathematically costs the least. Snowball targets the smallest balance, which clears a debt from your list soonest. This calculator shows both so you can see exactly what the motivational choice costs.
Avalanche if you are confident you will stick with the plan regardless. Snowball if you know you need visible progress to keep going. Research on real behaviour is genuinely split, and a plan you finish beats a cheaper plan you abandon.
It goes entirely to whichever debt your strategy is targeting, on top of all the minimums. It is the single biggest lever in the whole calculation - small increases shorten the plan much more than people expect.
Because at those payments the interest is growing at least as fast as you are paying it down. That is a real and dangerous situation, so the tool says so rather than showing a fake date decades away. Increasing the monthly amount will fix the projection.
Yes. When a debt clears, its minimum is added to the pot attacking the next debt. This roll-up is exactly why the method is called a snowball, and leaving it out would make every projection too slow.
Usually not. Mortgages are long-term and low-rate, so including one tends to swamp the plan. This tool is most useful for consumer debt - cards, overdrafts, car loans and personal loans.
No. The entire simulation runs in your browser. Nothing is uploaded, saved or retained after you close the tab.