Systems of Measurements used
in Health Care
METRIC SYSTEM
HOUSEHOLD SYSTEM
METRIC TERM – ABBREVIATION – STANDARD SYSTEM COMPARISON
Meter
m
Length/distance
Gram
g
Weight/mass
Liter
L*
Volume/capacity
Metric system is more accurate than the household system.
Metric is easier to convert between numbers because everything is
based on a unit of 10.
*Capital L is used for liter at all times, not lower case, can be confused
with number 1 or l.
TERM ABBREVIATION MEANING
Conversion within the decimal system are calculated by multiplying by 10,
100, 1000 and so on
1kiloliter=1000 X1 liter=1000liters
1hectoliter= 100 X 1 liter= 100 liters
1 decaliter= 10 X 1 liter= 10liters
1deciliter= 0.1 X 1 liter= 0.1 liter
1 centiliter= 0.01 X1 liter= 0.01liter
1milliliter= 0.001 X1 liter= 0.001 liter
***Gram or meter can be used in place of liter depending on what unit of
measurement is used**
Less Than One Unit of Measure
Length:
• 1 decimeter (dm) = 1/10 or 0.1 of a
meter
• 1 centimeter (cm) = 1/1 00 or 0.01
of a meter
• 1 millimeter (mm) = 1/1 000 or
0.001 of a meter
Volume:
• 1 deciliter (dL) = 1/10 or 0.1 of a liter
• 1 milliliter (mL) = 1/1 000 or 0.001 of a
liter
More Than One Unit of Measure
Weight:
• 1 .0 hectogram = 100 grams
• 1 .5 hectograms = 150 grams
• 1.0 kilogram = 1000 grams
• 1 .5 kilograms = 1500 grams
Length:
• 1 .0 hecto meter = 100 meters
• 1.5 hectometers = 150 meters
• 1.0 kilometer = 1000 meters
• 1.5 kilometers = 1500 meters
K
H
D
B
D
C M
KING=kilo
Henry=hecto
Died=deca
By=base unit of measurement
Drinking=deci
Chocolate=centi
Milk=milli
The Metric Number Line:
Another way to help you navigate inside
the metric system.
Kilo Hecto Deka * Deci
1000
100
10
1
0.1
Centi Milli
.01
.001
To use the Metric Line:
1. You will decide what unit you are
changing FROM and what unit you are
changing TO.
2. Starting at the FROM unit, count over
(keeping in mind- "left" or "right") to the
TO unit.
**This will be the number of places you will move
the decimal in your answer.
• EXAMPLE: 32 kilograms = ___________ grams
(This means you want to change FROM kilograms TO grams.)
Use the number line and count over, starting at
Kilograms….move to grams.
K
H
D
(grams) D
* -> 1 place- ->2 places- ->
3 places
C
M
Now we use the number of places you
moved (3 places to the "right") to find the
answer.
Move the decimal 3 places to the "right“
using a zero to hold each of the places
32 kilograms = 32000 grams
Don’t forget that every whole number has a
decimal to it’s right, so in our example
32kg is the same as saying 32.0 kg
(We don’t always write the decimal to the right of a number
but it is understood that it is there.)
Converting units within the metric system is accomplished by moving the
decimal point.
Example: A physician orders 2000milligrams of a medication
The medication is available in 2-gram tablets
Milligrams must be converted to grams
Milli is in the third place to the right of gram
Move the decimal point three spaces to the left toward gram:
2000=2.000 , or 2.
Change unit name to grams: 2grams
The proper dose would be 2 grams, or one 2-gram tablet.
**Converting from a larger to a smaller prefix or unit (kilo to milli): the
answer will be larger. **Converting from a smaller to a larger prefix or
unit (milli to kilo): the answer will be smaller.
**Millimeters (mL) and cubic centinmeters (cc) represent the same
amount. Both units measure volume, and they are often interchanged
when dispensing liquids. **1mL=1cc. 1mL or 1cc has a weight of
1gram.
Basic Rules for the Metric System
1. Numbers less than one unit are written in decimals.
Examples:
0.1
0.01
0.001
2. If there is no number before the decimal point, always add
a zero.
Examples:
.1 is 0.1
.5 is 0.5
.75 is 0.75
3. Abbreviations are always singular, never plural.
Examples:
Grams is abbreviated g, not gs.
Liters is abbreviated L, not Ls.
Liter is always shortened to capital L, not lowercase I.
4. Leave a space between the number and the abbreviation.
Examples:
10 g not lOg.
1000 ml not l000ml.
HOUSEHOLD SYSTEM
• Method of measurement most familiar to
US students.
• Units of measurement are related to each
other and can be converted among
themselves.
HOUSEHOLD SYSTEM
• Volume/capacity measurements:
–
–
–
–
–
Tablespoons (T or tbsp): 2T=1oz
Ounces (oz): 8oz=1C (cup)
Cups (C or cp): 2C=1pt
Pints (pt): 2pt=1qt
Quarts (qt): 4qt=1gal
HOUSEHOLD SYSTEM
• Distance/length measurement
– Inch(in or “) 12in =1ft
– Foot (ft or ‘): 3ft=1yd
– Yard (yd): 1,760yd=1mile
HOUSEHOLD SYSTEM
• Mass/weight measurements:
– Ounce (oz): 16oz=1lb
– Pound=lb
Converting Systems of
Measurement
• Health Care work requires that units from one system of
•
measurement be converted to those of another.
Requires knowledge of the equivalences between
systems
• Common approximate equivalents:
– Distance/length Capacity/volume
• 1in=2.5cm
1tsp=5ml=5cc
• 39.4in=1m
1oz=30ml=30cc
Mass/weight
2.2lb=1kg
Frequently, there are no exact equivalents, and the answer is a close
approximation when converting between systems.
STEPS FOR PERFORMING
CONVERSIONS
• Identify an equivalent between two systems
• Set up a proportion so unit measurements on each side
•
•
•
•
of the equation are the same
Use X for the unknown value being calculated
Cross-multiply (multiply the means and then multiply the
extremes)
Solve for X
Decide if the answer is reasonable
STEPS FOR PERFORMING
CONVERSIONS…CONT
• If converting from a smaller unit to a larger unit, the
answer will be smaller.
– Example: How many tsp are in 10ml?
• Known equivalent: 1tsp=5ml
• 1tsp: 5ml= X tsp.: 10ml
• X= 2tsp
STEPS FOR PERFORMING
CONVERSIONS….CONT
• If converting from a larger unit to a smaller unit, the
answer will be larger
– Example: How many pounds are in 6.8kg?
• Known equivalent: 2.2pd=1kg
• 2.2pd: 1kg= Xpd: 6.8kg
• X=14.96pounds
YouTube
• http://www.youtube.com/watch?v=5tHpD
zXP-lg
Standard and Metric Units of Length
Measuring Devices: Fluid Ounces
and Cubic Centimeters
Graduate
Baby’s bottle
Measuring cup
Converting Pounds and Kilograms
Converting pounds to kilograms
Multiply weight in pounds by 0.45
Examples:
110 lb changed to kilograms:
110 x 0.45 = 49.5 kg
200 lb changed to kilograms:
200 x 0.45 =90 kg
Converting kilograms to pounds
Multiply weight in kilograms by 2.2
Examples:
50 kg changed to pounds:
50 x 2.2 = 110 lb
90 kg changed to pounds:
90 x 2.2 = 198 lb
Converting Ounces to Metric
Measurements
•Converting ounces to cc/ml
Multiply volume in ounces by 30
Examples:
1 oz medicine 1 × 30 = 30 ml = 30 cc
8 oz water 8 × 30 = 240 ml = 240 cc
6 oz soup 6 × 30 = 180 ml = 180 cc
4 oz juice 4 × 30 = 120 ml = 120 cc
12 oz soda pop 12 × 30 = 360 ml = 360 cc
• Converting ounces to grams
Multiply weight in ounces by 30
Examples:
1 oz changed to grams: 1 × 30 = 30 g
8 oz changed to grams: 8 × 30 = 240 g
**Remember 1oz also equivalent to
1gram**
Metric/Household Conversion
Practice
•
•
•
•
•
•
•
•
•
30ml/cc=____oz
20kg=______lbs
2000g=______kg
3.5L=______ml
10 tsp=______cc
5yd =______m
100F=______C
38C=______F
8qts=______L
32oz=______cups
40.5lbs=______oz
5T=______ml
30ml=______tsp
850ml=______L
Metric/Household Conversion
Practice
• At the pediatrician’s office, Mr. Johnson observes you
documenting his daughter’s weight as 30kilograms. Mr.
Johnson asks you to tell him the weight in pounds.
• Mrs. Bennerman has been instructed to drink a liter of
water prior to her fetal ultrasound. She asks you how
many cups of fluid she will have to drink.
• The doctor has requested Mrs. Lim to give her toddler
30cc of Gatorade each hour after vomiting subsides.
Mrs. Lim would like to use a spoon for administering the
fluid. How many teaspoons/tablespoons will you tell her?
Question for Wednesday
• How many cc’s are in 1oz?
Question for Friday
• How many mm of gauze bandage is
needed to cover a wound that is 6cm in
length?
Question for Thursday
• How many milliliters are in four liters?
Question for Monday
• What is the length in inches of a newborn
baby measured to be 56cm?
Test Review
• A resident is to receive 1milligram of
medication per dose. If a solution has
8milligrams of medication in
40milliliters of solution, how much
solution should the resident receive?
Test Review
• A radiology patient needs to drink one liter
of contrast fluid prior to a procedure.
How many 250cc containers will the
patient need to drink?
Test Review
• Two yards of elastic bandage is needed to
wrap an athlete’s ankle. How many
meters of bandage will be used?
Test Review
• The number of ml that a 500cc container
can hold is:
Test Review
• A premature infant weighing 650grams
weighs how many milligrams?
Test Review
• How many mm of gauze bandage is
needed to cover a wound that is 6cm in
length?
Test Review
• The average adult brain weighs 4060ounces or how many kg?
Test Review
• Susie has been on a diet and has lost
4kilograms. How many pounds has she
lost?
Test Review
• Johnny weighed 13lbs on his 2month
check-up. How many kilograms did he
weigh?
Test Review
• The capacity of the right atrium is
approximately 1.9ounces. What does this
equal in cc’s?
Test Review
• How many mL of liquid medication can a
teaspoon hold?
Test Review
• Which kitchen utensil is BEST to use when
measuring 15mL of cough syrup?
Test Review
• What is the length in inches of a newborn
baby measured to be 56cm?
Test Review
• A surgical scar which measures 5.1cm is
how many inches long?
Test Review
• A surgeon removes a 100gm tumor from a
patient. How many ounces does this
tumor weigh?
Test Review
• Approximately how many kilograms does a
225 pound patient weigh?
Test Review
• 10 milliliters is equal to 10……
Test Review
• How many milliliters are in four liters?
Test Review
• How many cc’s are in one liter of fluid?
Test Review
• How many Kg are equal to 40lbs?
Test Review
• Patient has a temperature of 99degrees F.
What is their temperature in Celsius?
Test Review
• How many mL of liquid medication can a
teaspoon hold?
Test Review
• How many kg’s are equal to 40lbs?
Test Review
• 12,000L is equal to how many KL?
Test Review
• The capacity of the right atrium is
approximately 1.9ounces. What does this
equal in mL?
1ST Block Test ID
• 8911012841
• When you are done, please shut your
computer down, put it back in its
appropriate place, plug it back up
• Sit quietly and work independently until
others are finished
2nd Block Test ID
• 8922812841
• When you through with your test, please
log off and shut computer down, plug it
back in
• Sit quietly and work independently until
others are finished
3rd Block Test ID
• 8903412841
• When you are through, please log off and
shut your computer off, plug it back in.
• Sit quietly and work independently until
others are finished
4th Block Test ID
• 8919512841
• When you are through, please log off and
shut your computer off, plug it back in.
• Sit quietly and work independently until
others are finished