About Plain Money Math

Plain Money Math explains US personal finance topics — retirement accounts, index funds, credit card rewards — by working through the actual arithmetic instead of summarising it. Every article is written to answer one question completely, and every calculator shows the formula it uses.

Who writes this

Gautam Panchal writes and builds everything here. I am a software developer, not a licensed financial adviser, and this site reflects that: it explains how products and accounts work mechanically. It does not tell you what to do with your money, because I do not know your situation and am not qualified to.

How the numbers are checked

Figures come from primary sources — the IRS, the issuing bank’s own terms page, a fund’s prospectus — and each article lists the ones it relied on. Rules change every year, so articles carry a published date and an updated date, and anything rate- or limit-dependent gets revisited when the rules move. If you find something wrong, tell me and I will correct it and note the correction.

How this site makes money

Two ways, both disclosed. Display advertising, which is not targeted by anything you tell this site. And affiliate links, where a company pays a commission if you sign up through a link here — at no additional cost to you. Affiliate relationships never determine what gets covered or what the analysis concludes. When a product is a poor deal, the article says so, commission or not.

What this site will never do

• Recommend a specific security, or tell you to buy or sell.
• Publish a “best of” list ordered by commission rate.
• Ask for account numbers, passwords, or financial details.