Just some handy conversions. You’re expected to know the metric ones, not the imperial ones…but they can come in handy.

Metric

1cm = 10mm
1m = 100cm
1km = 1000m
1kg = 1000g
1 tonne = 1000kg
1 litre = 1000ml
1 litre = 1000cm3
1cm= 1ml

Imperial

Here’s some common metric to imperial conversions.

  • 1 km = 5/8 mile
  • 1 m = 39.37 inches
  • 1 foot = 30.5 cm
  • 1 inch = 2.54 cm
  • 1 kg = 2.2 lb
  • 1 gallon = 4.5 litres
  • 1 litre = 1 3/4 pints

Converting Speed

Convert the distance and the times separately.

Example: What is 48 km/h converted to m/s?

48km/h = (48 x 1000) m/h = 48 000 m/h

There are 3600 seconds in an hour. So:

48 000 m/h = (48 000/3600) m/s = 13.33333.. m/s

Converting Area And Volume

This is a classic exam mistake. 1m2 DOES NOT equal 100cm2

Here’s how to do it correctly:

1m2 = 100 cm x 100 cm = 10 000 cm2

1cm2 = 10 mm x 10 mm = 100 mm2

1m3 = 100 cm x 100 cm x 100 cm = 1 000 000 cm3

1cm3 = 10 mm x 10 mm x 10 mm = 1000 mm3