##### What is the issue?

The world's measures are far from standard, and we run multiple measures of temperature, distance, space etc depending upon which activity is being undertaken or which nation we happen to be in.##### Why address this?

To make sense of the data we need to use conversion tables.##### How to address this?

Here is a list of useful conversion tables that may turn out to be useful.To convert degrees Celsius into degrees Fahrenheit….Multiply by 1.8 and add 32

To convert degrees Fahrenheit to degrees Celsius….Subtract 32 and divide by 1.8

To convert Pounds (Ib) to Kilogrammes (kg) ....multiply by 0.4536

To convert Kilogrammes to Pounds .....multiply by 2.205

Water 1 litre weighs 1.00 kg/2.2 lb.

1 gallon weighs 4.53 kg/10 lb.

To convert Gallons to Litres ....multiply by 4.546

To convert Litres to Gallons ....multiply by 0.22

To convert Petrol to Weight ....1 litre weighs 0.73 kg/1.61 lb. 1 gallon weighs 3.36 kg/7.4 lb.

To convert Diesel to Weight .....1 litre weighs 0.84 kg/1.85 Ib.1 gallon weighs 3.86 kg/8.5 lb.

*Quick conversions:*

1 Imperial Gallon = 4.546 litres = 1.2 US Gallons

1 litre = 0.22 Imperial gallons = 0.264 US Gallons

1 US Gallon = 3.8 litres = 0.83 Imperial Gallons

To convert Inches to Centimetres (cm) ....multiply by 2.54

To convert Centimetres to Inches .....multiply by 0.393

*Quick conversions*

1 foot = 30.48 centimetres (cm)

1 yard = 0.9144 metre (m)

1 mile = 1.6093 kilometres (km)

1 millimetre = 0.03937 inch

1 centimetre = 0.0328 foot (ft)

1 metre = 1.094 yards (yd)

1 kilometre = 0.62137 mile

1 nautical mile = 1852 m

1 International mile = 1609.344 m

*Quick and dirty conversions*

Metres into yards add one-tenth

Yards into metres deduct one-tenth

Kilometres into miles multiply by 5 and divide by 8

Miles into kilometres multiply by 8 and divide by 5

Litres into pints multiply by 7 and divide by 4

Pints into litres multiply by 4 and divide by 7

Litres into gallons multiply by 2 and divide by 9

Gallons into litres multiply by 9 and divide by 2

Kilogrammes into pounds divide by 9 and multiply bv 20

To convert cubic feet to cubic metres .....multiply by 0.028

To convert 1 cu ft to fluid capacity .....it holds 6114 gallons of water weighing 62.31b

To convert square metres to square feet .....multiply by 10.764

To convert square feet to square metres .....multiply by 0.093

To convert square centimetres to square feet .....multiply by 0.001076

To convert square inches to square centimetres .....multiply by 6.451

1 knot = 1.1508 mph = 1.853 kmph

To convert Kilometres per hour to Miles per hour .....multiply by 0.6214

To convert Miles per hour to Kilometres per hour ....multiply by 1.609

To convert Kilometres per hour to Knots per hour ....multiply by 0.5396

To convert Knots per hour to Kilometres per hour ....multiply by 1.853

Larger displacement sailboats can usually travel faster than smaller boats because hull speed depends on the length of the boat’s waterline and the volume of water displaced. Maximum speed is a function off:

In Knots =1.34 x (the square root of the waterline length of boat) in feet

In Knots = 2.43 x (the square root of the waterline length of boat) in metres

In km/h = 4.5 x (the square root of the waterline length of boat) in metres

See 'the three magic numbers for optimum sailing comfort and efficiency'.

Distance = Speed x Time

Speed = Distance ÷ Time

Time = Distance ÷ Speed

60 D ST

Distance in knots

Speed in nautical miles per hour

Time in minutes

Speed = (60 x Distance) ÷ Time

Distance = (Speed x Time) ÷ 60

Time = (60 x Distance) ÷ Speed

Horsepower to Kilowatts: x 0.7457

Kilowatts to Horsepower: x 1.341

Amps equals watts divided by volts.

Example how long can I run a 1watt bulb on a 1 Ah battery:

Watts = Volts x Amps

1 W = 12V x i, i = 1 W / 12 V, i = .083 Amps

Time = (Amp-hours / Amps) / (Safety Factor)

t = (1 Ah / .083 A) / 2, t = (15.6 hours) / 2, t = 6.2 hours

Distance to the horizon in nautical miles = 1.17 x (square root of your eye height)

Distance at which an object becomes visible = 1.17 x (square root of your eye height) + 1.17 x (square root of the height of the object)

Atmospheric pressure at sea level = 14.7 psi

For each foot of water depth, pressure increases 0.445 psi

Pressure doubles every 33 feet

Example: Calculate pressure at a depth of 66’ 66’ x 0.445 psi / ft = 29.37 + 14.7 = 44.1 = 3 atmospheres For each 1,000 feet in altitude, pressure decreases 1 foot of head or 0.433 psi, so at 2,000 feet above sea level, pressure would be 14.7 – 2 x 0.433 = 13.83

Average at sea level: 29.92 inches = 1013.2 millibars (range 950 mb – 1035 mb) Inches of mercury x 33.86 = Millibars

Millibar ÷ 33.86 = Inches of mercury

##### With thanks to:

Michael Harpur, Yacht Obsession
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