SI units

International System of Units (SI)

The seven SI base units

 

LENGTHS

rule

 1 Kilometre = 1000 metres

To convert from metres to kilometres, multiply by 1000.

To convert from kilometres to metres, divide by 1000.

 

  1

Change Km to m
X 1000

1 Km

=

1000 m

5 Km

=

5000 m

3.7 Km

=

3700 m

13.9 Km

=

13900 m


Change m to Km
÷ 1000

900 m

=

0.9 Km

1900 m

=

1 .9 Km

33400 m

=

33.4 Km

1 metre = 100 centimetres

To convert from metres to centimetres, multiply by 100.

To convert from centimetres to metres, divide by 100.

j

 

Change m to cm
X 100

1 m

=

100 cm

10 m

=

1000 cm

5.4 m

=

540 cm

10.2 m

=

1020 cm


Change cm to m
÷ 100

8 cm

=

0.08 m

71 cm

=

0.71  m

3400 cm

=

34 m

 1 centimetre = 10 millimetres

To convert from centimetres to millimetres, multiply by 10.

To convert from millimetres to centimetres, divide by 10.

3

Change cm to mm
X 10

1 cm

=

10 mm

5 cm

=

50 mm

8.7 cm

=

87 mm

15.2 cm

=

152 mm


Change mm to cm
÷ 10

5 mm

=

0.5 cm

55 mm

=

5 . 5 cm

555 mm

=

55. 5 cm

 

Imperial to Metric

1 inch = 2.54 cm
1 foot = 0.3048 m
1 mile = 1.609344 x 103 m

 

Imperial units

12 inches = 1 foot
3 feet = 1 yard
22 yards= 1 chain
10 chains = 1 furlong
8 furlongs = 1760 yards = 1 mile
6080 feet = 1 nautical mile
6 feet = 1 fathom

Mass

11

1 Tonne = 1000 Kilogrammes

To convert from tonnes to kilogrammes, multiply by 1000.

To convert from kilogrammes to tonnes, divide by 1000.

6

 

Change Tonnes to Kilogrammes
X 1000

1 Tonne = 1000 Kg
2 Tonnes = 2000 Kg
0.8 Tonne = 800 Kg

Change Kilogrammes to Tonnes
÷ 1000

185 Kg = 0.185 Tonnes
2kg = 0.002 Tonnes
1450 Kg = 1.45 Tonnes

1 kilogramme = 1000 grammes

To convert from kilogrammes to grammes, multiply by 1000.

To convert from grammes to kilogrammes, divide by 1000.

8

Change Kilogrammes to grammes
X 1000

5 Kg = 5000 g
0.8 Kg = 800 g
5.47 Kg = 5470 g

Change grammes to Kilogrammes
÷ 1000

4500 g  = 4.5 Kg
152 g  = 0.152 Kg
1450 g = 1.45 Kg

 

1 gramme = 1000 milligrammes

To convert from grammes to milligrammes, multiply by 1000.

To convert from milligrammes to grammes, divide by 1000.

11

Change grammes to miligrammes
X 1000

20g = 20,000 mg
450 g = 450,000 mg
      42.5 g = 42500 mg

Change miligrammes to grammes
÷ 1000

45 mg  = 0.045 g
152 mg  = 0.152 g
1450 mg = 1.45 g

 

Imperial to Metric

1 ounce = 2.834952 x 10-2 kg
1 pound = 0.45359237 kg
1 stone = 6.350293 kg

Imperial units

6 ounces (oz) = 1 pound 
14 pounds (lb) =  1 stone
28 pounds = 1 quarter
4 quarters = 1 hundredweight
20 hundredweight (cwt) = 1 ton

VOLUME

jug

1 Litre  = 100 Centilitres ( cl )
= 1000 millilitres ( ml )
= 1000 cubic centimetres ( cm3 )

1 Cubic Metre (m3)  = 1000 Litres

To convert from cubic metres to litres, multiply by 1000.

To convert from litres to cubic metres, divide by 1000.

 

12

 

Change m3 to L
                X 1000

2  m3  = 2000 L
75  m3 = 75000 L
0.08  m3  = 80 L

Change L to m3
÷ 1000

45 L = 0.045  m3  

5 L = 0.005  m3  

7544 L = 7.544  m3  

 

1 centilitre  ( cl ) = 10 mililitres

To convert from centilitres to millilitres, multiply by 10.

To convert from millilitres to centilitres, divide by 10.

12

 

Imperial to Metric

   1 fluid ounce = 2.841306 x 10-5 m3
    1 gallon = 4.54609 x 10-3 m3
   1 gallon USA = 3.785412 x 10-3 m3

20 fluid ounces  (fl. oz) = 1 pint
2 pints (pt) = 1 quart
4 quarts = 1 gallon

One gallon is the volume occupied by exactly 10 pounds of water of density 0.988859 gram per millilitre , weighed in air of density 0.001217 gram per millilitre against weights of density 8.136 grams per millilitre.

© Alexander Forrest