Metric Conversion

Distance

One yard is currently defined as exactly 0.9144 metres

Therefore:

1 yard = 3 feet
1 foot = 12 inches
1 inch = 0.9144 ÷ 3 ÷ 12 × 100 = 2.54 cm
1 mile = 1760 yards
1 mile = 0.9144 × 1760 ÷ 1000 = 1.609344 km

Volume

One imperial gallon is currently defined as exactly 4.54609 litres

One litre is defined as one cubic decimetre

One US gallon is currently defined as exactly 231 cubic inches

Therefore:

1 litre = 1 ÷ 4.54609 ≈ 0.2199692483 imperial gallons
1 cubic inch = 2.54 ^3 = 16.387064 cubic cm (millilitres)
100 cubic cm (millilitres) = 100 ÷ 2.54^3 ≈ 6.1023744095 cubic inches

231 inches = 3√231 * 0.254 ≈ 1.5584912797 dm
1 US gallon = 231 cubic inches ≈ 1.5584912797 ^3 ≈ 3.785411784 cubic dm (litres)

Weight

One pound is currently defined as exactly 0.45359237 kg

Therefore:

1 pound = 16 oz
1 kg = 1 ÷ 0.45359237 ≈ 2.2046226218 pound ≈ 35.2739619496 oz
100 g ≈ 3.527396195 oz
1 oz = 0.45359237 × 1000 ÷ 16 ≈ 28.349523125 g

References

-- Frank Dean - 14 May 2018