Our purpose
Money decisions are easier when you can see the numbers. CentSum provides free calculators that answer common questions such as "what will my mortgage payment be?", "how much of my paycheck do I keep?" and "how long will it take to pay off this card?". Each page also explains the maths in plain English so you understand the result, not just the number.
Who is behind CentSum
CentSum is built and maintained by Rizwan Ali, a software developer and AI researcher. The calculators and guides are written and tested by Rizwan Ali, with figures taken from the public sources listed on each page (the IRS, CFPB, Federal Reserve, Social Security Administration and others). Rizwan Ali is not a financial adviser or tax professional, and nothing on this site is personal financial advice.
How we work
- Accurate first. Every calculation is covered by automated tests that compare results with known answers and independent formulas.
- Sourced. Tax figures come from IRS publications and other named sources listed on our methodology page.
- Private. Calculations run in your browser. The numbers you type are not sent to us. If you choose to save a scenario or tick a checklist step, it is kept only in your own browser.
- Independent. We do not sell loans, insurance or investment products, and no lender pays to influence a result.
- Kept current. Tax data is reviewed every year and whenever the IRS publishes new figures.
How the site is funded
The site is free to use. It may display advertising, which is clearly labelled and kept separate from the calculators and articles. Advertising never changes how a calculation works. See our privacy policy for details on how ads use cookies.
What we are not
We are not a financial adviser, tax preparer, lender or law firm. Results are estimates for education and planning. For decisions that matter, please confirm the figures with a qualified professional or your lender. Read our terms and disclaimer.
Spotted a mistake?
Accuracy matters to us. If you think a figure or explanation is wrong, please email hello@centsum.com. We review every report and correct errors promptly.