Apothecary
/ Metric and Other Conversion Equivalents
Abbreviation
of Measures

gal
or gals 
=
gallons 
g 
=
gram 
O,
pt or pts 
=
pints 
kg 
=
kilogram (1,000g) 
oz
or ozs 
=
ounces 
mg 
=
milligram (^{1}/_{1,000}g) 
fl.oz 
=
fluid ounces 
mcg
or µg 
=
microgram (^{1}/_{1,000,000}g) 
lb
or lbs 
=
pounds 
L
or l 
=
litre (or liter in US) 
st 
=
stones 
cl 
=
centilitre (^{1}/_{100} L) 
gtts 
=
drops 
ml 
=
millilitre (^{1}/_{1000} L) 
iu 
=
international units 
µl 
=
microlitre (^{1}/_{1,000,000} L) 
m or min 
=
minims 
meq
or mEq 
=
Milliequivalent 
hr 
=
hour 
m 
=
metre (or meter in US) 
min 
=
minutes 
mm 
=
millimetre (^{1}/_{1,000} m) 
sec 
=
seconds 
cc
or cu.cm 
=
cubic centimetres (^{1}/_{1,000} L) 
ft 
=
foot or feet 
dr 
=
dram or drachm 
gr 
=
grains 
sc 
=
scruple 
t
or tsp 
=
teaspoon 
T
or tbsp 
=
tablespoon 

• One
litre of pure water weighs approx. one kilogram so 1cc of water
weighs 1 gram.
• A steel paper clip weighs about 1 gram.
• "A spoonful" means heaped or rounded, with as much
above the bowl of the spoon as in the spoon. Obviously, a measure
of liquid is a level spoonful. 
Liquid
Metric Conversions

1
gallon (gal)(US) 
=
3785 ml 
1
gallon (UK) 
=
4546 ml 
1
pint (pt)(US) 
=
473.18 ml 
1
pint (UK) 
=
568.26 ml 
16
fluid ounces (US) 
=
473.18 ml 
20
fluid ounces (UK) 
=
568.26 ml 
8
fluid ounces (US) 
=
236.59 ml 
10
fluid ounces (UK) 
=
284.13 ml 
4
fluid ounces (US) 
=
118.29 ml 
5
fluid ounces (UK) 
=
142.07 ml 
1
fluid ounce (fl.oz)(US) 
=
29.57 ml 
1
fluid ounce (UK) 
=
28.41 ml 
 
 
 
 
1cc
= 1g 
=
1ml (approx) 
1
teaspoon 
=
5 ml (approx) 
10
minims 
=
0.616 ml 
1
tablespoon 
=
15 ml (approx) 
15
to 16 drops ( gtts ) 
=
1 cc = 1ml 
1
drop 
=
1 minim approx 
Note:
Spoon and drop conversions should be regarded as approximations
due to the different surface tensions and specific gravity of
various liquids. 
Solid
Metric Conversions

1
pound (avoirdupois) 
=
453.592 g 
1/2
grain 
=
30 mg 
1
pound (apothecary) 
=
373.242 g 
1/4
grain 
=
15 mg 
1
ounce (avoirdupois) 
=
28.35 g 
1/8
grain 
=
8 mg 
1
ounce (apothecary) 
=
31.10 g 
1/12
grain 
=
5 mg 
15
grains 
=
1 g 
1/100
grain 
=
600 mcg 
10
grains 
=
600 mg 
1/150
grain 
=
400 mcg 
7
1/2 grains 
=
500 mg 
1/200
grain 
=
300 mcg 
5
grains 
=
300 mg 
1/250
grain 
=
250 mcg 
1
1/2 grains 
=
100 mg 
1/300
grain 
=
200 mcg 
1
grain 
=
64.79891 mg 
1
kilogram 
=
2.2 pounds 
1
pound 
=
0.45 kilograms (kg) 
1
stone 
=
6.35 kg 
1000
mcg 
=
300 to 7000 iu (below) 
1000
mcg 
=
1 mg 
1
scruple 
=
1.2 g 
1
drachm 
=
28.8 g 
Note
on International Units ( i.u. )
An old measurement of vitamin activity determined by biological
methods as opposed to new measures that are determined by direct
chemical analysis.
Many health foods and supplements still use i.u. ( IU ).
For Vitamin A, 1 i.u. = 0.3µg retinol, 3.6µg bcarotene,
or 7.2µg other vitamin A carotenoids
For Vitamin D, 1 i.u. = 0.025µg cholecalciferol
For Vitamin E, 1 i.u. = 0.67µg natural atocopherol (different
conversion factors are used for different forms of vitamin E)

Ratios
and Percent Solutions

1:100 
= 1g/100ml
[10mg/ml] 
= 1% 
1:200 
= 500mg/100ml
[5mg/ml] 
= 0.5% 
1:1,000 
= 100mg/100ml
[1mg/ml] 
= 0.1% 
1:5,000 
= 20mg/100ml
[200mcg/ml] 
= 0.02% 
1:10,000 
= 10mg/100ml
[100mcg/ml] 
= 0.01% 
Calculation
of Milliequivalents (mEq)
mEq
= Weight
(grams) / mEq Weight (grams)
Ion
or Compound 
mEq
W.(g)

Ion or Compound

mEq W.(g) 
Na+ 
0.023 
HC03 
0.061 
K+ 
0.039 
NaCl 
0.0585 
Ca++ 
0.020 
KCl 
0.0745 
Mg++ 
0.012 
CaCl.2H2O 
0.0735 
NH4+ 
0.018 
NH4Cl 
0.0535 
Cl 
0.0355 
MgSO4.7H20 
0.123 
Lactate 
0.089 
NaHCO3 
0.084 
Acetate 
0.059 
Ca Gluconate 
0.224 
Citrate 
0.063 
Phosphorus 
0.031 
For milliequivalent
weights not shown, use the formula:
milliequivalent weight (mEq W.) = Atomic
Weight (g) / (Valence) x 1,000
Drug
Administration Times

Standardised
medication administration times should be followed as much
as possible. The following table shows those hours of the
day which are to be used as standardised times of medication
administration. If the prescriber wishes the first dose
to be administered before the earliest available standardised
time then the prescriber should state "expedite" or "first
dose now" with the drug order.
In ICU's the first dose of a newly ordered parenteral antibiotic
regimen should be administered within 2 hours unless specified
otherwise by the prescriber.

Ordered
Time

Hour(s)
to be given

QAM 
08 
QD 
08 
QHS 
21 
QPM 
17 
BID 
08
17 
Q12H 
08
20 
Q8H 
08
16 24 
TID 
08
12 17 
TID
AC 
07
12 17 
TID
W/M 
0730
1230 1730 
QID 
08
12 17 21 
Q6H 
06
12 18 24 
AC
& HS 
07
12 17 21 
PC
& HS 
08
13 18 21 
1
HR AC & HS 
0630
1130 1630 2100 
1
HR PC & HS 
0830
1330 1830 2100 
5
X's/day 
06
1030 15 1930 23 
Q4H 
04
08 12 16 20 24 
Common Terms and Abbreviations
Term
or Phrase

Abbreviation

Meaning

ad 
ad 
to, up
to 
ad libitum 
ad. lib. 
at pleasure 
ana 
a.a. 
of each 
ante cibos 
a.c. 
before
meals 
aqua 
aq. 
water 
bis in
die 
b.i.d. 
twice
a day 
collyrium 
collyr. 
eye lotion 
cum 
c. 
with 
cum aqua 
cum aq. 
with water 
dentur
tales doses 
d.t.d. 
give such
doses 
dispensa 
disp. 
dispense 
et 
et 
and 
gutta,
guttae 
gtt. 
drop,
drops 
hora somni 
h.s. 
at bedtime 
in vitro 
in vit. 
in glass 
misce 
m. 
mix 
non repetatur 
non. rep. 
do not
repeat 
oculus
dexter 
o.d. 
right
eye 
oculus
sinister 
o.s. 
left eye 
omni die 
o.d. 
daily 
omni mane 
o.m. 
every
morning 
omni nocte 
o.n. 
every
night 
per os 
p.o. 
by mouth 
placebo 
placebo 
to please 
post cibos 
p.c. 
after
meals 
pro re
nata 
p.r.n. 
as the
occasion arises 
quantum
sufficiat 
q.s. 
sufficient
quantity 
quater
in die 
q.i.d. 
four times
a day 
recipe 
Rx 
take 
semis 
ss _ 
onehalf 
sine 
s,s 
without 
si opus
sit 
s.o.s. 
if necessary 
ter in
die 
t.i.d. 
three
times a day 
trochiscus,
torchisci 
troch. 
lozenge,
lozenges 
unguentum 
ungt. 
ointment 
ut
dictum 
ut
dict. 
as directed 
Estimating Lean Body Weight
Lean
Body Weight Calculation: 
Males
50kg + 2.3kg per each inch over 5 feet of height 
Females
45kg + 2.3kg per each inch over 5 feet of height 
In
patients whose actual weight is > 20% over the above calculated
ideal body weight, add 40% of the difference between the actual
and the calculated ideal weights to the calculated ideal weight
to arrive at a corrected ideal body weight.
1kg = 2.2 lbs. 14 lbs. = 1 stone = 6.35 kg 
Height 
Estimated
Lean Body Weight
(+) or (  ) 2.3kg per inch over/under 5 feet tall
(+) 50kg for men or (+) 45.5kg for women

Imperial
/ metric

Males
(kg)

Females
(kg)

4 ft 8
in / 142 cm

40.8

36.3

4 ft 9
in / 145 cm

43.1

38.6

4 ft 10
in / 147 cm

45.4

40.9

4 ft 11
in / 150 cm

47.7

43.2

5 ft 0
in / 152 cm

50.0

45.5

5 ft 1
in / 155 cm

52.3

47.8

5 ft 2
in / 157 cm

54.6

50.1

5 ft 3
in / 160 cm

56.9

52.4

5 ft 4
in / 163 cm

59.2

54.7

5 ft 5
in / 165 cm

61.5

57.0

5 ft 6
in / 168 cm

63.8

59.3

5 ft 7
in / 170 cm

66.1

61.6

5 ft 8
in / 173 cm

68.4

63.9

5 ft 9
in / 175 cm

70.7

66.2

5 ft 10
in / 178 cm

73.0

68.5

5 ft 11
in / 180 cm

75.3

70.8

6 ft 0
in / 183 cm

77.6

73.1

6 ft 1
in / 185 cm

79.9

75.4

6 ft 2
in / 188 cm

82.2

77.7

6 ft 3
in / 191 cm

84.5

80.0

6 ft 4
in / 193 cm

86.8

82.3

6 ft 5
in / 196 cm

89.1

84.6

6 ft 6
in / 198 cm

91.4

86.9

6 ft 7
in / 201 cm

93.7

89.2

6 ft 8
in / 203 cm

96.0

91.5

For metric
conversions go to a unit starting with

a
b c
d e
f g
h i
j k
l m
n o
p q
r s
t u
v w
y


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