Guides
Learn the concepts behind the conversions — written to be genuinely useful, not padding.
Metric vs Imperial: A Practical Guide
Understand the difference between the metric and imperial systems, why both still exist, and how to convert between them confidently.
How to Convert Between Units (The Right Way)
Learn the universal method for converting any unit using conversion factors and dimensional analysis, with worked examples.
US Gallon vs UK Gallon: What's the Difference?
The US gallon and the imperial (UK) gallon are not the same size. Here's the difference and how to convert each one correctly.
Temperature Scales Explained: Celsius, Fahrenheit, Kelvin
How Celsius, Fahrenheit, Kelvin, and Rankine relate, why temperature conversions use an offset, and the exact formulas.
The Metric System and SI Units Explained
A clear introduction to the metric system, SI base units, and the prefixes that make it so easy to scale.
Significant Figures and Precision in Conversions
How rounding and significant figures affect conversion accuracy, and how to choose the right precision for your task.
Torque Units Explained: Newton-metres, Foot-pounds and Inch-pounds
What torque actually measures, why newton-metres and foot-pounds are not interchangeable with energy units, and how to convert between the three units you will meet on a torque wrench.
Force Units: Newtons, Kilogram-force and Pound-force
Why kilograms measure mass but kilogram-force measures force, where the factors 9.80665 and 4.4482216152605 come from, and how to convert between newtons, kgf and lbf.
Electrical Unit Prefixes: milli, micro, kilo and mega
How SI prefixes work across ohms, amps, volts, farads and henries — why component values jump in factors of 1000, and how to convert between mA, µA, kΩ, MΩ and mH without slipping a decimal place.