Metric and Imperial: A Quick Conversion Guide
Switching between metric and imperial units comes down to a few key conversion factors. Learn the important ones and the rest follow.
Length
The anchor is that one inch equals exactly 2.54 centimetres. From there: a foot is 30.48 cm, a mile is about 1.609 km, and a metre is about 3.28 feet. The metric units (mm, cm, m, km) scale neatly in powers of ten.
Weight
One pound equals about 0.4536 kilograms, so a kilogram is roughly 2.205 pounds. Within imperial, 16 ounces make a pound and 14 pounds make a stone — the latter still common for body weight in the UK and Ireland.
Temperature and volume
Temperature isn't a simple multiplication: to go from Celsius to Fahrenheit, multiply by 1.8 and add 32. For cooking volumes, remember a US cup is about 237 ml and differs from the 250 ml metric cup, so check which system your recipe uses.