Express all specific measured quantities (dimensions, degrees, weights, distances, sums of money, etc.) in numeral form.
Correct
Incorrect
1.3 seconds or 1.3 sec
One point three seconds
$25,000
Twenty-five thousand dollars
2 amp
two amperes
Write numbers beginning a sentence as words.
Correct
Incorrect
Twenty-three screws are included.
23 screws are included.
Write approximate or non-specific numbers in a sentence as words.
Correct
Incorrect
about half; a quarter of; four times as often.
about ½; a ¼ of; 4 times as often.
'60s, '70s & '80s or 1960s, 1970s or 1980s
60s, 70s, & 80s or Sixties, Seventies, and Eighties
Hyphenate all compound numbers from twenty-one through ninety-nine in a sentence.
Correct
Incorrect
There are twenty-three screws included.
There are twenty three screws included.
Write decimals as numbers. Place a zero in front of decimals with no whole number.
Correct
Incorrect
0.128 mm
.128 mm
1.33 mm
One point three millimeters
Don't use a space between whole numbers and fractions. Use fractions on the web.
Print Correct
Incorrect
1½
11/2
2⅔
2-2/3
Web Correct
Incorrect
2-3/4
2 3/4
1-1/2"
1.5"
Use a space between numbers and units of measure.
Correct
Incorrect
89 mm Piston & Liner Set
89mm Piston & Liner Set
Do not use a space between numbers and measurement signs.
Correct
Incorrect
11%
11 %
A 36° angle.
A 36 ° angle.
5' 3"
5 ' 3 "
Use decimals with temperature scales. Do not express temperature degrees with the ° symbol. Use a space after the number.
Correct
Incorrect
15.1 F
15.1F
-45 C
-45°C
2,700 K
.045 °K
For imperial measurements, use fractions for print, and decimals for web.
Print Correct
Print Incorrect
5⁄16
0.3125"
Painted, 60 spoke, 15" x 4 ½"
Painted, 60 spoke, 15"x4.5"
Web Correct
Web Incorrect
Painted, 60 spoke, 15" x 4.5"
Painted, 60 spoke, 15" x 4 ½"
Use decimals with metric.
Correct
Incorrect
7.9375 mm
0.3125"
Units of measure are case-sensitive. mm is millimeter (one thousandth of a meter) Mm is megameter (1,000,000 meters)
Correct
Incorrect
A 5 mm x 0.8 mm pitch tap
A 5 MM x 0.8 mm pitch tap."
Treat unit names like ordinary nouns when spelled out in full. Thus the names of units start with a lower-case letter, except at the beginning of a sentence or in a title. When repeating multiple measurements consider spelling out the unit name for the first instance then using the abbreviation on following instances.
Unit Name
Unit of Measure
Use
millimeter
mm
1 mm
centimeter
cm
6 cm
amperes/amps
amp or A
4 A
volts
V
8 V
watts
W
12 W
joules
J
6.7 J
lumens
lm
142 lm
ohms
ohms
10 Ω
decibels
dB
120 dB
hertz
Hz
160 Hz
inches
" or in
6 in
feet
' or ft
14 ft
pound
lb
10 lb
ounce
oz
10 oz
AM/PM
am/pm
8 am
pressure (pounds per square inch)
psi
35 psi
torque (foot-pounds)
ft-lb
80 ft-lb
torque (inch-pounds)
in-lb
120 in-lb
Do not use "plural" units of measure.
Correct
Incorrect
2 mL
2 mLs
14 lb
14 lbs
Do not use a period after a unit of measure. They are not abbreviations.
Correct
Incorrect
14 lb
14 lb.
12' 9"
12 ft. 9 in.
Express dimensions by length, width, and height/depth, separated by an "x" with spaces in between. List dimension units when needed for clarification.
Correct
Incorrect
48" x 12" x 2"
48"x12"x2"
8.5 cm x 11 mm x 1 cm
8.5cmx11mmx1cm
Size: 7½"(l) x 7⅘"(w) x 2¾"(h) with 3" end stop
Size: 71/2" (L)x74/5" (W)x23/4" (H) with 3" end stop
Do not mix imperial and metric.
Correct
Incorrect
21.59 cm x 1 mm
8 ½" x 1 mm
Do not mix symbols and units.
Correct
Incorrect
1" x 6' Easy Loom
1" x 6 ft Easy Loom
1 in x 6 ft Easy Loom
1" x 6 ft Easy Loom
For a range of numbers, use an n-dash with no spaces before or after. For dates, use the full year for the first date and the 2 digit abbreviation for the second.
Correct
Incorrect
Dia: 15"–16"; Grip: 2 3/4"–3 1/8"
Dia: 15" - 16"; Grip: 2 3/4" – 3 1/8"
1968-73
1968 - 73
Add a space after w/
Change "O" ring to O-ring
' (single prime)
" (double prime)
‘’ (single quotation marks)
“” (double quotation marks)
’ (apostrophe)
° Bullets - bullets are thoughts and don't have periods at the end. Bullets are a single sentence. They are more than 1 sentence make 2 bullets or rewrite.
