Practical guides
Each guide answers one precise question, cites its sources and leads to the tool that does the math for you. The figures come from the same engines as our tools.
Guides
- Why a 1 TB drive shows as 931 GBTB or TiB, GB or GiB: where the gap comes from and how to work it out.
- How to create a strong passwordThe NIST rules, and why length beats symbols.
- Color contrast: the WCAG thresholds explainedThe AA and AAA thresholds, how the ratio works, and examples.
- Inches, feet and centimeters: the exact conversionsThe exact definitions, and converting a height in feet and inches.
- Celsius and Fahrenheit: the formula and benchmarksThe exact formula both ways, benchmarks and the mental shortcut.
- Percent or percentage points: the differencePoints or percent: two ways to measure the same change.