Long-form posts on real-world percentage math: shopping discounts, inflation, loans, tipping, compound interest. Written by the maintainers of FreePercentCalc.
A "5% cashback" card sounds obviously better than a "2% cashback" card. Run the math against your actual spending and the cheaper-looking option often wins. Here's the framework.
Read the article →The "average wedding costs $35,000" headline is real, but the breakdown by line item is where the planning either works or breaks. Here's the percentage-by-category map for 2026.
Read the article →Retailers love stacking percentages — "20% off, then an extra 15% at checkout" — and shoppers reliably add the two numbers in their head. Here's why that math is wrong, and what you're actually paying.
Read the article →A $3,000 vacation can quietly cost $90–$180 extra in FX fees you never see itemized. Here's where the money leaks, and the cards and tools that plug each hole.
Read the article →Half your income on needs, 30% on wants, 20% on savings. The simplest budget rule in personal finance is also one of the easiest to misuse. Here's where it works, where it breaks, and how the percentages need to bend in 2026.
Read the article →Headline inflation has cooled. Your purchasing power probably hasn't recovered. Here's how to put real numbers to "did my raise keep up" — and why the answer depends on more than the CPI number on TV.
Read the article →The "rent is throwing money away" cliché is wrong about half the time. The 5% rule and the price-to-rent ratio give you the actual answer for your city, your math, and 2026 mortgage rates.
Read the article →A lower monthly payment is not a better deal. The dealer's spreadsheet knows this; most buyers don't. Here's the four numbers you should be checking before you sign anything.
Read the article →A 20% tip in New York is generous. The same 20% in Tokyo is rude. Here's the practical math for tipping in 2026, and a quick framework for figuring out the right number anywhere in the world.
Read the article →A one-percentage-point fee on your retirement fund sounds harmless. Compounded for thirty years, it costs you a year of retirement income. Here's the math the fund prospectus didn't show.
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