How to Convert Units Correctly: Length, Weight, and Temperature

Unit conversion errors are surprisingly common and can have serious consequences — from the Mars Climate Orbiter crash (1999) caused by a metric/imperial mismatch, to medical dosing errors.

Key conversions to know: 1 inch = 2.54 cm (exact), 1 kg = 2.20462 lbs, Celsius to Fahrenheit: F = (C × 9/5) + 32, Fahrenheit to Celsius: C = (F - 32) × 5/9. For temperature, remember it is not a simple ratio conversion — you must account for the offset.