About SmartCashLab
SmartCashLab makes free payoff and cash calculators that show, in plain numbers, what a money decision could cost or save you. Enter your own figures, compare the options side by side, and decide with the math in front of you.
What SmartCashLab is
SmartCashLab is a small, independent website of free calculators for everyday debt and cash questions: whether a payoff strategy saves interest, how much time an extra payment takes off a loan, or whether a fee pays for itself. There is no account to create and nothing to download.
Our calculators
- Biweekly mortgage calculator: compare biweekly and monthly mortgage payments and see the interest and time you could save.
- Car loan payoff calculator with extra payments: see how paying extra each month changes your car loan payoff and total interest.
- Balance transfer calculator: check whether a balance transfer fee pays for itself, your breakeven month, and your net savings after the fee.
How the calculators work
Every calculation runs in your browser. The numbers you type are not sent to us or stored by us. Each calculator page explains its method and assumptions, such as how interest is charged each month and when payments are applied, so you can see exactly what the result is based on.
Results are estimates, not advice or a quote. Lenders, servicers, and card issuers set their own terms and may calculate interest differently, so your actual figures can differ. Check the details with your lender or card issuer before you act.
How we make money
SmartCashLab is free to use. Some pages may include links to financial products or services, and some of those may be affiliate links: if you click one and apply or sign up, we may earn a commission at no extra cost to you. Compensation never changes the math. The calculators give the same result whether or not a product pays us. Read our affiliate disclosure for details.
Editorial independence
We decide what to build and what to write. No affiliate partner reviews or approves our calculators or explanations before they are published, and none can pay to change a result. When a page lists products or services to compare, it is a starting point for your own research, not a recommendation that a product suits you.
Methodology and accuracy
We test each calculator against worked examples before it is published, and the examples on each page come from those tests. We aim for accuracy, but mistakes can happen. If you think a number or explanation is wrong, please tell us through our contact page and we will review it and correct the page if needed.
What SmartCashLab is not
SmartCashLab is not a financial advisor, lender, broker, or card issuer. We do not make loans, arrange credit, or decide who is approved. Nothing on this site is financial, tax, or legal advice. For decisions about your own situation, consider talking with a qualified professional.