Who we are
DebtMathLab is run by two friends who work with money every day. One of us is a Chartered Accountant at a US stock-market firm and builds and checks the maths behind every calculator. The other helps people in the UK and the US plan their debt payoff and keeps up with new government rules that affect borrowers.
We started DebtMathLab because we kept seeing the same problem: people know they should “pay more than the minimum,” but nobody shows them what that actually changes. These calculators show it in plain numbers. Even so, everything on this site is general education, not personal financial advice.
Why we built these calculators
Debt is easier to tackle when you can see the finish line. Many online calculators hide their assumptions or ask for an email address before showing results. Ours show the result straight away and explain the exact formula on every page.
How the calculators work
- They use standard amortization maths: interest is APR รท 12 each month, payments are applied after interest, and multi-debt plans roll each paid-off minimum into the next debt.
- Every calculator is checked against independent calculations, and the worked examples on each page are reproduced exactly by the tool.
- Results are estimates. Real statements can differ because of daily interest, fees, rate changes or new purchases.
Your privacy
Everything you type into a calculator stays in your browser and is never sent to us. Read our Privacy Policy for the full details.
How the site is funded
The calculators are free because the site shows advertising through Google AdSense. Ads are always labelled “Advertisement” and never affect calculator results or what we write. We don’t accept payment to recommend lenders or products.
Our app
We’re building a free DebtMathLab app for Android that will save your debts and track your progress month by month. It’s coming soon.
Get in touch
Found an error, or have a suggestion? Visit our Contact page or email contact@debtmathlab.com.