Weights and Measures Act 1985

Sections 1(2), 8(1).

SCHEDULE 1 Definitions of Units of Measurement

PART I Measurement of Length

Imperial units
Mile	= 1760 yards.
Yard	= 0.9144 metre.
Foot	= 1 /3 yard.
Inch	= 1 /36 yard.
Metric units
Kilometre	= 1000 metres.
Metre	is the length of the path travelled by light in vacuum during a time interval of 1 /299 792 458 of a second.
Decimetre	= 1/10 metre.
Centimetre	= 1/100 metre.
Millimetre	= 1/1000 metre.

PART II Measurement of Area

Imperial units
Acre	= 4840 square yards.
Square yard	= a superficial area equal to that of a square each side of which measures one yard.
Square foot	= 1/9 square yard.
Metric units
Hectare	= 100 ares.
Decare	= 10 ares.
Are	= 100 square metres.
Square metre	= a superficial area equal to that of a square each side of which measures one metre.
Square decimetre	= 1/100 square metre.
Square centimetre	= 1/100 square decimetre.
Square millimetre	= 1/100 square centimetre.

PART III Measurement of Volume

Metric units
Cubic metre	= a volume equal to that of a cube each edge of which measures one metre.
Cubic decimetre	= 1/1000 cubic metre.
Cubic centimetre	= 1/1000 cubic decimetre.
Hectolitre	= 100 Hires.
Litre	= a cubic decimetre.
Decilitre	= 1/10 litre.
Centilitre	= 1/100 litre.
Millilitre	= 1/1000 litre.

PART IV Measurement of Capacity

Imperial units
Gallon	= 4.546 09 cubic decimetres.
Quart	= 1 /4 gallon.
Pint	= 1 /2 quart.
Gill	= 1 /4 pint.
Fluid ounce	= 1/20 pint.
Metric units
Hectolitre	= 100 litres.
Litre	= a cubic decimetre.
Decilitre	= 1/10 litre.
Centilitre	= 1/100 litre.
Millilitre	= 1/1000 litre.

PART V Measurement of Mass or Weight

Imperial units
Pound	= 0.453 592 37 kilogram.
Ounce	= 1/16 pound.
Ounce troy	= 12/175 pound.
Metric units
Tonne, metric tonne	= 1000 kilograms.
Kilogram	is the unit of mass; it is equal to the mass of the international prototype of the kilogram.
Hectogram	= 1/10 kilogram.
Gram	= 1/1000 kilogram.
Carat (metric)	= 1/5 gram.
Milligram	= 1 /1000 gram.

PART VI Definitions of Certain Units Which May Not be Used for Trade

Measurement of length

Furlong	= 220 yards.
Chain	= 22 yards.

Measurement of area

Square mile	= 640 acres.
Rood	= 1210 square yards.
Square inch	= 1/144 square foot.

Measurement of volume

Cubic yard	= a volume equal to that of a cube each edge of which measures one yard.
Cubic foot	= 1/27 cubic yard.
Cubic inch	= 1/1728 cubic foot.

Measurement of capacity

Bushel	= 8 gallons.
Peck	= 2 gallons.
Fluid drachm	= 1/8 fluid ounce.
Minim	= 1/60 fluid drachm.

Measurement of mass or weight

Ton	= 2240 pounds.
Hundredweight	= 112 pounds.
Cental	= 100 pounds.
Quarter	= 28 pounds.
Stone	= 14 pounds.
Dram	= 1/16 ounce.
Grain	= 1/7000 pound.
Pennyweight	= 24 grains.
Ounce apothecaries	= 480 grains.
Drachm	= 1/8 ounce apothecaries.
Scruple	= 1/3 drachm.
Metric ton	= 1000 kilograms.
Quintal	= 100 kilograms.

PART VII Measurement of Electricity

1	(a) ampere	is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2 x10-7newton per metre of length.
	(b) OHM	is the electric resistance between two points of a conductor when a constant potential difference of 1 volt, applied between the two points, produces in the conductor a current of 1 ampere, the conductor not being the seat of any electromotive force.
	(c) VOLT	is the difference of electric potential between two points of a conducting wire carrying a constant current of 1 ampere when the power dissipated between these points is equal to 1 watt.
	(d) WATT	is the power which in one second gives rise to energy of 1 joule.
2.	Kilowatt	= 1000 watts.
	Megawatt	= one million watts.