## Measurements

**Systems of Measurement**

Most of the world now uses the metric system of measurement. In the UK metric measurements have been taught in schools since the early 1970’s; however imperial measurements are still used in some cases. We therefore have to know how to convert between metric and imperial measurements.

**The Metric system**

The metric system has almost universally been adopted as it is much easier to calculate accurately as all metric measurements are based on units of 10.

Milli – means one thousandth (or 1/1000)

Centi means one hundredth (or 1/100)

Kilo means one thousand (1,000)

**Metric Measurements**

Length is typically measured in:

Centimetre (cm) = 10mm

Metre (m) = 100cm

Kilometre (km) = 1,000m

Mass is measured in:

Kilogram (kg) = 1,000 grams

Tonne = 1,000kg

Volume is measured in:

Litre = 1,000ml

1,000 litres = 1m^{3}

**Imperial Measurements**

Length is measured in:

1 foot = 12inches

1 yard = 3 feet

1 mile = 1760 yards

Mass is measured in:

1 pound = 16 ounces

1 stone = 14 pounds

1 ton = 160 stones

Volume is measured in:

1 gallon = 8 pints

**Converting Metric and Imperial Units**

As some imperial units are still in use today you do need to know how to convert them to metric and vice versa. The conversion rates below have been rounded to 2 decimal points.

**Kilometres and Miles:**

Miles to km - Multiply by 1.61

km to Miles - Multiply by 0.62

**Kilograms and Pounds:**

kg to Pounds - Multiply by 2.20

Pounds to kg - Multiply by 0.45

**Litres and Gallons:**

Litres to Gallons - Multiply by 0.22

Gallons to Litres - Multiply by 4.55

**Metres and Centimetres to feet and inches:**

Inch to cm - Multiply by 2.54

cm to Inch - Multiply by 0.39