About Debtcal
Built to help you become debt-free — faster.
Debtcal is a free collection of financial calculators designed to give every American a clear, honest picture of their debt — and a realistic plan to escape it.
Rachel Monroe
Founder & Personal Finance Educator
I spent eight years as a financial analyst — first at a regional bank, later at a consumer lending firm — before pivoting to personal finance education. During that time I reviewed thousands of loan files and saw first-hand how badly most people misunderstand the true cost of carrying debt.
I built Debtcal because the calculators that already exist are either buried inside product pitches or too simplified to be useful. This site does one thing: it runs the numbers honestly and explains what they mean.
I hold a B.S. in Finance from the University of Illinois and am an Accredited Financial Counselor® (AFC®) candidate.
Our mission
Debtcal exists to close the information gap between people carrying debt and the financial institutions that profit from it. Our tools are free, permanently ad-supported (never paywalled), and built to show you exactly how interest compounds so you can make smarter decisions — whether that's paying an extra $50 a month or choosing between the debt avalanche and debt snowball strategies.
We do not sell financial products, accept referral fees, or recommend specific lenders. Our only revenue comes from display advertising. That independence is what keeps the math honest.
How our calculators work
Credit Card Payoff Calculator
Interest is calculated using the standard daily periodic rate method: APR ÷ 365 × daily balance. At the end of each billing cycle (30 days) we apply the interest charge, then allocate your monthly budget payment across cards using either the avalanche method (highest APR first) or snowball method (lowest balance first). Minimum payments are enforced on every card at every step. Results match the methodology published by the Consumer Financial Protection Bureau (CFPB).
Loan Payoff Calculator
We use the standard amortization formula to derive the base monthly payment: M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1] where P = principal, r = monthly interest rate, and n = total payments. Extra payments (monthly, yearly, or one-time lump sum) are applied directly to principal at the time they occur, which reduces the outstanding balance used to calculate future interest. The resulting amortization table and interest-saved figures are recalculated in full on every input change.
All formulas are reviewed annually against guidance from the CFPB and the FDIC. Last verified: April 2025.
Disclaimer
The calculators and articles on Debtcal are provided for informational purposes only and do not constitute financial, legal, or tax advice. Results are estimates based on the inputs you provide and mathematical models — they are not guarantees of future outcomes. Your actual payoff timeline and interest costs will depend on your lender's specific terms, fees, and billing practices. Always consult a qualified financial professional before making significant financial decisions.
Get in touch
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