How formats work — and how to convert between them fast.
Calculate any time zone difference in two steps: convert local time to UTC, then add the target zone's offset…
Data sizes smallest to largest, in order: bit, byte, KB, MB, GB, TB and beyond — with the exact byte values,…
How the same number is written in binary, decimal, hex, octal, and Roman numerals — with worked examples that…
How the everyday text conversions really work — changing case, making URL slugs, counting words vs bytes, URL…
The small unit, date, and text conversions people do every week — with worked examples you can check by hand,…
How everyday unit conversions actually work — length, weight, temperature, cooking measures, and data sizes —…
How timezones, UTC offsets, Unix timestamps, and date arithmetic really work — with worked examples that comp…
What hex codes, rgb(), and hsl() actually mean, how to convert between them by hand with worked examples that…