# 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:

**Measurement** | **Units** |

Length | Millimetre (mm), centimetre (cm), metre (m), kilometre (km) |

Volume/Capacity | Millilitre (ml), litre (l) |

Mass | Gram (g), kilogram (kg) |

**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**.*

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