From the blog
Conversion Guides & Reference Articles
Practical how-to guides, formula breakdowns, and reference tables for the world's most searched unit conversion questions.
Temperature
How to Convert Celsius to Fahrenheit: Formula, Tables and Oven Settings
The exact formula, °C/°F tables, oven settings with gas marks, and where the double-and-add-30 shortcut goes wrong.
Length
Meters to Feet: Exact Formula, Feet-and-Inches Table and Examples
The exact 0.3048 factor, a m to ft-and-inches table, the decimal-feet trap, floor areas and shortcut accuracy.
Weight
Kilograms to Pounds: Chart, Exact Formula and Worked Examples
The exact 1959 definition, a kg/lb chart, luggage and gym examples, stones, and how accurate each mental shortcut is.
Height
How Tall Is 180 cm in Feet and Inches?
180 cm = 5 ft 10.87 in (5′ 11″). The method, a height table both ways, and how it compares with official averages.
Pressure
Bar to PSI for Tire Pressure: Exact Conversion, Table and Placard Example
Exact bar, psi and kPa factors, a tire-range table, a placard example, and why gauges read gauge pressure.
Cooking
US Cups to Grams: Flour, Sugar, Butter and 15 More Ingredients
Grams per cup for 18 ingredients, why King Arthur and USDA differ, and the US, label, metric and UK cups compared.
Clothing
How to Read International Clothing Size Charts
US, UK, DE, FR, IT and JIS sizes explained, with conversion tables, EN 13402 and how to read a brand's chart.
Fuel Economy
MPG to L/100 km: US and UK Gallons, Tables and the MPG Illusion
The 235.21 and 282.48 constants, US vs UK gallons, a conversion table, the MPG illusion and MPGe for EVs.
Music
MIDI Note Numbers and Frequencies: Chart, Formula and Middle C
Every C from 8.18 Hz to 8,372 Hz, the note-to-Hz formula both ways, and why note 60 is called C3, C4 or C5.
Global
Metric vs Imperial: Which Countries Really Use Which?
Beyond the 'only three countries' myth: metric law vs daily use, the UK and Canada's mixed habits, and US vs imperial units.
Shoe Sizes
How to Convert Shoe Sizes: US, UK, EU, Japan and China
Measure your foot in cm, then convert: formulas, men's and women's charts, the two US women's scales and why EU charts differ.
Pressure
Pressure Units Explained: Pascal, Bar, PSI, Atmosphere and mmHg
Exact definitions of Pa, bar, psi, atm, Torr and mmHg, a conversion table, and gauge vs absolute pressure.