Appendix 4 - Useful conversion factors

Length:

1 centimetre = 0. 3937 inches
1 inch = 2.54 centimetres
1 metre = 1.0936 yards = 3.2808 feet = 39.370 inches
1 kilometre = 0.6214 miles
1 mile = 1.6093 kilometres

Area:

1 hectare = 10 000 square metres = 0.1 square kilometres = 2.471 acres = 11 960 square yards

1 acre = 0.4047 hectares = 4 047 square metres = 4 840 square yards = 43 450 square feet

1 square kilometre = 0.3861 square miles = 100 hectares = 247.1 acres

1 square mile = 2.5898 square kilometres = 254.98 hectares = 640 acres

Volume:

1 litre = 1 000 millilitres = 61.026 cubic inches = 0.21998 Imperial gallons = 0.26418 U.S. gallons

1 Imperial gallon = 4.5460 litres = 1.20096 U.S. gallons

1 U.S. gallon = 0.83267 Imperial gallons = 3.78528 litres

1 U.S. barrel = 42 U.S. gallons = 34.972 Imperial gallons = 0.15899 cubic metres

1 cubic metre = 1 000 litres = 35.3148 cubic feet = 1.30795 cubic yards = 219.97 Imperial gallons = 264.18 U.S. gallons = 6.290 U.S. barrels

1 m³ solid = 750 kg. fuelwood with 40% moisture

Mass:

1 kilogram = 2.2046 pounds = 1 000 grams

1 pound = 453.592 grams = 0.4536 kilograms

1 ton, English = 2 240 pounds = 1 016.05 kilograms = 1.01605 tonnes (metric tons) = 1.12 U.S. tons = 20 hundred weight (cwt)

1 tonne = 1 000 kilograms = 0.98421 tons (English) = 1.10231 U.S. tons = 2 204.62 pounds

1 U.S. ton = 2 000 pounds = 17.8572 hundred weight (cwt) = 907.184 kilograms = 0.907184 tonnes = 0.89286 tons (English)

Density:

Bulk density of commercial charcoal = 250 to 300 kilograms per cubic metre

Approx. weight of a stacked metre (stere) of:

- Plantation grown radiate pine (partly seasoned) = 550 to 650 kilograms

- Plantation grown Eucalypt wood (partly seasoned) = 600 to 700 kilograms

- Medium density tropical hardwood (partly seasoned) = 700 to 800 kilograms

- Dense tropical hardwood = 900 kilograms

Energy:

1 kilowatt = 1.3405 horsepower

1 horsepower = 0.746 kilowatts

1 kilojoule = 0.2389 kilogram calories = 0.948 British thermal units (BTU) = 0.001 megajoules = 0.00027778 kilowatt hours

1 kilowatt hour = 3 412 British thermal units = 1.34 horsepower hours = 3 600 kilojoules = 3.6 megajoules

Prefix table:

1012	tera	T
109	giga	G
106	mega	M
10³	kilo	k
10²	hecto	h
10	deca	da

Heating Value: (See conversion factors to calculate values in other units)

Fuel	High Heating
Green wood*	15 000
Dry wood*	19 000
Charcoal	31 000
Coke	30 000
Bituminous coal	27 000
Fuel oil	44 000
Kerosene	46 000
Wood tar	20 000
Natural gas	45 000
Producer gas	5 000
Wood retort gas	6 000

* Influence of moisture on heating value of wood:
Net heating value (MJ/kg) = 19 000 - 220.
where is moisture content in percentage of total weight.