In these tables it is necessary to differentiate between the "international foot" and the "survey foot;" the survey foot is underlined. When the name of a unit is enclosed in brackets (thus, [1 hand] . . . ), this indicates (1) that the unit is not in general current use in the United States, or (2) that the unit is believed to be based on "custom and usage" rather than on formal authoritative definition. Equivalents involving decimals are, in most instances, rounded off to the third decimal place except where they are exact, in which cases these exact equivalents are so designated. The equivalents of the imprecise units "tablespoon" and "teaspoon" are rounded to the nearest milliliter.

UNITS OF MASS

1 assay ton (AT)	29.167 grams.
1 carat (c)	200 milligrams (exactly).
	3.086 grains.
1 dram apothecaries (dr ap or )	60 grains (exactly).
	3.888 grams.
1 dram avoirdupois (dr avdp)	27-11/32 (= 27.344) grains.
	1.777 grams.
1 gamma (y)	1 microgram (exactly).
1 grain	64.798 91 milligrams (exactly).
1 gram (g)	15.432 grains.
	0.035 ounce, avoirdupois.
1 hundredweight, gross or long	112 pounds (exactly).
(gross cwt)	50.802 kilograms.
1 hundredweight, gross or short	100 pounds (exactly).
(cwt or net cwt)	45.359 kilograms.
1 kilogram (kg)	2.205 pounds.
1 microgram (ug) [the Greek letter mu
in combination with the letter g]	0.000 001 gram (exactly).
1 milligram (mg)	0.015 grain.
	437.5 grains (exactly).
1 ounce, avoirdupois (oz avdp)	0.911 troy or apothecaries ounce.
	28.350 grams.
1 ounce, troy or apothecaries	480 grains (exactly).
(oz t or oz ap or )	1.097 avoirdupois ounces.
	31.103 grams.
1 pennyweight (dwt)	1.555 grams.
1 point	0.01 carat.
	2 milligrams.
	7000 grains (exactly).
1 pound, avoirdupois (lb avdp)	1.215 troy or apothecaries pounds.
	453.592 37 grams (exactly).
1 pound, troy or apothecaries	5760 grains (exactly).
(lb t or lb ap)	0.823 avoirdupois pound.
	373.242 grams.
1 scruple (s ap or )	20 grains (exactly).
	1.296 grams.
	2240 pounds (exactly).
1 ton, gross or long	1.12 net tons (exactly).
	1.016 metric tons.
	2204.623 pounds.
1 ton, metric (t)	0.984 gross ton.
	1.102 net tons.
	2000 pounds (exactly).
1 ton, net or short	0.893 gross ton.
	0.907 metric ton.