Read the assumptions.

Compact explanations for the decisions behind common conversions: what the units mean, which value is the base, and where formats leave room for ambiguity.

NOTE 01A practical unit conversion referenceExact customary-unit relationships, decimal and binary data units, and rounding.→NOTE 02Percentage change and percentage pointsThree formulas that answer different questions, with baseline-zero limits.→NOTE 03Unix timestamps, UTC and local timeSeconds versus milliseconds, and why local wall time needs a timezone.→NOTE 04CSV quoting and JSON arraysEscaping commas and quotes, choosing headers, and keeping types honest.→

Each note links to a working tool and the standard or reference used for format-specific details.