Medication - Metric Conversions
Metric units and conversions for the calculation and administration of medication.
Basic Metric Units for drug administration
|
Quantity |
Unit |
Symbol |
|
length |
metre |
m |
|
mass |
gram |
g |
|
volume |
litre |
l |
|
time |
second |
s |
Common Units of Measurement for drug administration
The various quantities of these units often have a prefix to make writing quantities more succinct. For example 0.000001g may be written as 1 mcg (or 1µg.)
|
Prefix |
Symbol |
Multiplication factor |
|
mega |
M |
1,000,000 |
|
kilo |
k |
1,000 |
|
hecto |
h |
100 |
|
deka |
da |
10 |
|
unit |
e.g. g, m, l or s |
1 |
|
deci |
d |
0.1 |
|
centi |
c |
0.01 |
|
milli |
m |
0.001 |
|
micro |
mcg or µ |
0.000001 |
Converting a number from one metric unit to another involves moving the decimal place to the left or the right. To work out how many decimal places to move:
- Identify the metric scale
- Identify the two units in the problem
- Count the number of units from the current unit to the desired unit
- Move the decimal point the number of places from the given unit to the desired unit
Example 1 - Convert 0.1 grams to milligrams.
The decimal point is moved 3 places to the right - 0.1 g = 100 mg
Example 2 - Convert 375 millilitres to litres.
The decimal point is moved 3 places to the left - 375 ml = 0.375 l
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