Worked examples

Distance: 10 km × 0.621371 = 6.2137 miles. Weight: 70 kg × 2.20462 = 154.3234 pounds. Volume: 20 litres × 0.264172 = 5.28344 US gallons. Temperature: 25°C × 9/5 + 32 = 77°F. Length: 180 cm × 0.393701 = 70.86618 inches.

To convert the other way, divide instead of multiplying: miles ÷ 0.621371 gives kilometres, pounds ÷ 2.20462 gives kilograms, US gallons ÷ 0.264172 gives litres, and inches ÷ 0.393701 gives centimetres. For Fahrenheit to Celsius, subtract 32 first, then multiply by 5/9. For example, 77°F minus 32 is 45, times 5/9 is 25°C, which returns you to the starting figure above — a good check that the pair of formulas is consistent.