UNITS OF MEASURE

Metric System
• Use the abbreviations only when a numeric quantity precedes the unit of measure. DO not add an s to indicate plural form.
E.g. 10 cm 5 mm

• Do not capitalize most metric units of measure or their abbreviations. Learn the obvious exceptions and consult appropriate references for guidance.
E.g. dB – decibel Hz – hertz L – liter

• Use the decimal form with metric units of measure even when dictated as fractions, unless they are not easily converted
E.g. D: four and a half millimeters T: 4.5 mm not 41.2 mm
D: four and a third millimeters T: 4-1/3 mm

Non-Metric System
• Spell out common nonmetric units of measure (ounce, pound, inch, foot, yard, mile, etc.) to express weight, depth, distance, height, length, and width, except in tables. Do not use an apostrophe or quotation marks to indicate feet or inches, respectively (except in tables).

E.g. 4 pounds 5 ounces 14 inches 5 feet
5 feet 3 inches NOT 5’3” NOT 5 ft. 3 in.

• Do not abbreviate most nonmetric units of measure, except in tables. Use the same abbreviation for both singular and plural forms; do not add s.
E.g. 5 in. (use in, only in a table)

Punctuation
Commas
• do not use comma or other punctuation between units of the same dimension.
E.g. The infant weighed 5 pounds 3 ounces.
He is 5 feet 4 inches tall.

Hyphens
• Use hyphen to join a numbr and a unit of measure when they are used as an adjective preceding a noun.
E.g. 4.5-mm incision 8-inch wound 8-pound 5-ounce baby girl

• Avoid separating a numeral from its accompanying unit of measure (abbreviated or not) at the end of a line. If technology allows, use a required space, coded space, or nonbreaking space between them to assure that the numerals move to the next line along with the abbreviation.
E.g. …………………………………..5 cm
not …………………………….5
cm
Series
*Do not repeat units of measure in a related series unless their absence will confuse the reader.
E.g. The daily dose were 140, 135, and 58 mL, respectively.
4 x 5-cm mass