DebtMathLab
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Get out of debt faster with a plan you can see

Free calculators that show your exact debt-free date, the interest you'll pay, and the fastest way to pay it all off.

Find my debt-free date See all calculators
  • Private: numbers stay on your device
  • Every formula explained
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When will your credit card be paid off?

Change the numbers to match your statement. Results update when you press Calculate.

Debt-free in

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Months to pay off
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Total interest
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Total paid
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Interest this month
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Estimates for education only. Your lender may calculate interest differently.

How it works

Three steps to your debt-free date

  1. List what you owe

    Balance, interest rate and minimum payment for each debt. Your statements show all three.

  2. Pick your strategy

    Snowball clears small balances first for quick wins. Avalanche saves the most interest. Compare both.

  3. Follow your plan

    Pay every minimum, put spare money on one debt, and roll it over when that debt is gone.

Free tools

Calculators for every step of your journey

Each one explains its formula with a worked example, so you can check the maths yourself.

Coming soon

Your plan, soon in your pocket

We're building a free DebtMathLab app for Android. Save your debts, log every payment and watch your debt-free date move closer.

Android app coming soon
Guides

Learn how to beat debt for good

Read all guides

Why these calculators exist

Most debt advice says “pay more than the minimum” without showing what that actually changes. These calculators do the maths for you: they show the month you’ll be debt-free, the total interest you’ll pay, and exactly how much a bigger payment or a different payoff order saves.

Each calculator page explains the formula it uses with a worked example, so you can check every number yourself. Nothing you type is stored or sent anywhere.

Where to start

FAQ

Frequently asked questions

Are these calculators really free?

Yes. Every calculator is free and needs no account. The site is paid for by advertising, and every ad is clearly labelled.

Do you see or store the numbers I type?

No. All calculations run in your browser. The balances, rates and payments you enter are never sent to our server.

How accurate are the results?

They use standard amortization maths and match what a lender would calculate for a fixed rate with monthly interest. Real statements can differ slightly because many cards charge interest daily and may add fees.

Which payoff method should I use?

The avalanche method never costs more interest than the snowball method. The snowball method pays off your first debt sooner, which keeps some people motivated. Our snowball and avalanche calculators show both results for the same debts.