Precision unit conversion
A free online unit converter covering length, weight, temperature, volume, speed, area, data storage, pressure, energy, power, time, angles, fuel economy, currency, precious metals, force, torque, frequency, oven temperatures and Gas Mark, shoe and clothing sizes, and number bases. Convert between UK and US units instantly, right in your browser.
There are 25.4 millimetres in one inch. So 1 inch equals 25.4mm, and 43¾ inches works out to roughly 1111.25mm.
Multiply kilograms by 2.20462 to get pounds. For example, 10kg is about 22.05lb.
Gas Mark 4 is 180°C, which is 350°F. It's one of the most common UK baking temperatures.
A UK (imperial) gallon is 4.54609 litres — larger than a US gallon, which is 3.78541 litres.
A troy ounce (used for gold, silver and other precious metals) is 31.1g, while a standard avoirdupois ounce is 28.35g — troy ounces are about 10% heavier.
Multiply by 9/5 and add 32. So 20°C is 68°F, and 100°C (boiling point of water) is 212°F.
One kilometre is about 0.621 miles. To go the other way, one mile is roughly 1.609km.
Every category above also has a dedicated reference page with formulas, worked examples and answers to common questions — plus longer practical guides for cooking, baking, DIY and precious metals.