Apothecary, Avoirdupois & Unusual Conversions

Apothecary is a historical name for a medical professional who formulates and dispenses materia medica to physicians, surgeons and patients — a role now served by a pharmacist (or, especially in British English, a chemist or dispensing chemist).

The avoirdupois system is a system of weights (or, properly, mass) based on a pound of sixteen ounces. It is the everyday system of weight used in the United States, and is still widely used to varying degrees by many people in Ireland, Canada, the United Kingdom, and some other former English colonies despite the official adoption of the metric system. - Wikipedia

These apothecary, avoirdupois, and other unusual units and conversion factors are not typically found in engineering work, but are still fairly common in some fields like medicine. Now, finding a contemporary application for the scruple or the chain is highly unlikely, but if you ever need them or any other of these strange measures, well, you know where to go now. Dry measures, liquid measures, solid measures and others are mixed in.

1 pound (Av) 453.592 g
1 pound (Ap) 373.242 g
1 ounce (Av) 28.35 g
1 ounce (Ap) 31.10 g, 480 grains
15 grains 1 g
10 grains 600 mg
7 1/2 grains 500 mg
5 grains 300 mg
1 1/2 grains 100 mg
1 grain 64.79891 mg
1 pound 0.45 kg
1000 mcg 300 to 7000 iu (see right)
1 scruple 1.2 g, 20 grains
1 gal 3785 ml, 4 qts, 0.833 Imp gal
1 pt 473.18 ml
1 fl oz 29.57 ml
1 cc 1 gm, 1 ml
1 minim 1 drop, 0.0616 ml
1 tsp 5 ml
1 tsp 15 ml
1 stone 6.35 kg
1 dram 3 scruples
1 hundredweight 100 lbs
1 ton 2000 lbs
1 long ton 2240 lbs
1 pt 4 gills
1 hogshead 63 gallons
1 pipe or butt 2 hogsheads
1 tun 2 pipes
1 mile 320 rods
1 peck 2 gallons
1 bushel 4 pecks
1 fathom 6 ft, 2 yds
1 furlong 1/8 mile, 660 ft, 220 yds
1 league 3 mi, 24 furlongs
1 chain 100 links, 22 yds
1 acre 43560 sq ft, 0.40 hectare, 10 sq chains
1 sq rod 625 sq links
1 square 100 sq ft
1 board ft 144 cu in
 
Ap = Apothecary mg = milligram
Av = Avoirdupois g = gram
mcg = microgram kg = kilogram
gal = gallon ml = milliliter
fl oz = fluid ounce qt = quart
gr = grain gtts = drops
 sc = scruple st = stone
l or L = liter oz = ounce
ft = foot pt = pint
in = inch lb = pound
yd = yard cc = cubic centimeters
mi = mile Imp gal = Imperial gallon
m = meter dr = drachm = drachma = dram
 
Vitamin A, 1 i.u. = 0.3µg retinol, 3.6µg b-carotene, or 7.2µg other vitamin A carotenoids

Vitamin D, 1 i.u. = 0.025µg cholecalciferol

Vitamin E, 1 i.u. = 0.67µg natural a-tocopherol (other conversion factors used for other forms of vitamin E)