Common units of measurement
In practice, the most commonly used units differ from each other by a factor of 1000, and the names of some of these have been highlighted previously in Table 2. As an example of this, you can see in Figure 5 how the units of weight - tonne (t), kilogram (kg), gram (g), milligram (mg), and microgram (μg) - differ from each other by a factor of 1000.
Figure 5: Common units of measurement differ by a factor of 1000
It takes 1000 kilograms to make 1 tonne, so if you had a value written in kilograms you could convert it to tonnes by dividing by 1000 and re-labelling it as tonnes (i.e. 500 kg = 0.5 t). Similarly, you could convert a value written in tonnes to kilograms by multiplying by 1000 (so 2 t = 2000 kg).