Converting metric units

​​In a nutshell

The metric system involves a set of measurements based on metres, litres and grams. For each measurement there are subcategories which you need to be able to convert between. 

The metric measures

Metric measurements are used to describe lengths, volumes and mass. Below is a table of the units used: 

​

Note: The units in brackets are the shorthand format of each measurement. 

Conversion rates

For metric units there are some conversion rates you will have to know. 

​$$1km = 1000m$$​​

​$$1m = 100cm$$

$$1cm = 10mm$$​​​

​$$1 l = 1000ml$$​​

​$$1kg = 1000g$$

Converting between metric units

You can convert between metric measurements by multiplying and dividing by $$10$$, $$100$$ and $$1000$$. 

Example 1

Derek has $$1500ml$$ of juice. How much is this in litres​? 

There are $$1000$$ millilitres in $$1$$ litre.

$$1000ml = 1l$$​ 

Divide by $$1000$$ to convert millilitres​ to litres.

​$$1500 ml \div 1000 = 1.5 l$$

​

Therefore, Derek has $$\underline{1.5 \ litres}$$ of juice.

Note: The conversion is the same for grams to kilograms​.  

Example 2

Convert $$20cm$$ to metres and millimetres​. 

There are $$10$$ millimetres in $$1$$ centimetre.

​$$10mm = 1cm$$​​

Multiply by $$10$$​ to convert centimetres to millimetres.​

​$$20cm \times 10 = 200mm$$​​

There are $$100$$ centimetres in $$1$$ metre.

​$$100cm = 1m$$​​

Divide by $$100$$ to convert centimetres to metres.

​$$20cm \div 100 = \underline{0.2m}$$​​