The sections in this topic discuss when to use numerals and when to spell out numbers, how to treat fractions and ordinal numbers, when to use commas in numbers, and how to treat ranges of numbers.
The use of numerals versus words is primarily a matter of convention. For consistency in Microsoft documentation, follow these conventions:
In body text, use numerals for 10 and greater. Spell out zero through nine if the number does not precede a unit of measure or is not used as input. For round numbers of 1 million or more, use a numeral plus the word, even if the numeral is less than 10.
Microsoft style
10 screen savers
3 centimeters
Type 5, and then click OK.
1,000
five databases
zero probability
7 million
7,990,000
Not Microsoft style
2 disks
0 offset
eighteen books
twelve functions
1 thousand
7 million 990 thousand
Use numerals for all measurements, even if the number is less than 10. This is true whether the measurement is spelled out, abbreviated, or replaced by a symbol. Measurements include distance, temperature, volume, size, weight, points, picas, and so on, but generally not days, weeks, or other units of time. Bits and bytes are also considered units of measure.
Microsoft style
0 inches
3 feet, 5 inches
3.5-inch disk
0.75 gram
35mm camera
8 bits
1-byte error value
24 hours a day
seven days a week
two years
Not Microsoft Style
24/7
If it is necessary to save space in areas such as tables and the user interface, you can use all numerals, even for zero through nine.
Use numerals in dimensions. In most general text, spell out by, except for screen resolutions. For those, use the multiplication sign x (in HTML, ×).
Microsoft style
8.5-by-11-inch paper
640 x 480
Use numerals to indicate the time of day.
To accommodate the worldwide audience, use the 24-hour time notation if you can. Use 00:00, not 24:00, to indicate midnight. If you must use A.M. and P.M., use capital letters and periods. Using 12:00 A.M. or 12:00 P.M. to refer to noon or midnight is confusing. If you are consistently using 24-hour notation, 00:00 and 12:00 are unambiguous. In any case, just specifying noon or midnight is sufficient.
Microsoft style
The meeting is at noon.
The show begins at 19:00 Pacific Time (UTC-8).
The date changes at exactly midnight.
Not Microsoft style
The meeting is at 12 P.M.
The show begins at seven o’clock in the evening Pacific Time (UTC-8).
The date changes at exactly at 12:00 A.M.
To avoid confusion, always spell out the name of the month. The positions of the month and day are different in different countries. For example, 6/12/2000 can be interpreted as either June 12, 2000, or December 6, 2000.
Microsoft style
June 12, 2010
December 6, 2010
Not Microsoft style
6/12/10
12/6/09
Maintain consistency among categories of information; that is, if one number in a category requires a numeral, use numerals for all numbers in that category. When two numbers that refer to separate categories must appear together, spell out one of them.
Microsoft style
One booklet has 16 pages, one has 7 pages, and the third has only 5 pages.
ten 12-page booklets
Use numerals to indicate the coordinates of tables or worksheets and numbered sections of documents.
Microsoft style
row 3, column 4
Volume 2
Chapter 10
Part 5
step 1
Represent numbers taken from examples or the user interface exactly as they appear in the example or the user interface.
Use an en dash, not a hyphen, to form negative numbers: –79.
Do not start a sentence with a numeral unless you have no other choice. If necessary, add a modifier before a number. If starting a sentence with a number cannot be avoided, spell out the number.
Microsoft style
Lotus 1-2-3 presents options in the menu.
Microsoft Excel has 144 functions.
Eleven screen savers are included.
The value 7 represents the average.
Not Microsoft style
1-2-3 presents options in the menu.
144 functions are available in Microsoft Excel.
11 screen savers are included.
7 represents the average.
Hyphenate compound numbers when they are spelled out.
Microsoft style
Twenty-five fonts are included.
the forty-first user
Express fractions in words or as decimals, whichever is most appropriate for the context. Do not express fractions with numerals separated by a slash mark except as noted later in this section.
Hyphenate spelled-out fractions used as adjectives or nouns. Connect the numerator and denominator with a hyphen unless either already contains a hyphen.
Microsoft style
one-third of the page
two-thirds completed
three sixty-fourths
In tables, align decimals on the decimal point.
Insert a zero before the decimal point for decimal fractions less than one. When representing user input, however, do not include a zero if it is unnecessary for the user to type one.
Microsoft style
0.5 inch
type .5 inch
When units of measure are not abbreviated, use the singular for quantities of one or less, except for zero, which takes the plural.
Microsoft style
0.5 inch
0 inches
5 inches
If an equation containing fractions occurs in text, you can use the Microsoft Word Equation Editor to format it. Or, to insert a simple fraction, use a slash mark ( / ) between the numerator and the denominator.
Microsoft style
1/2 + 1/2 = 1
Ordinal numbers designate the place of an item in a sequence, such as first, second, and so on.
Cardinal numbers | Ordinal numbers |
|---|---|
One, two | First, second |
31, 32 | Thirty-first, thirty-second |
161 | One hundred sixty-first |
Spell out ordinal numbers in text, even when more than nine; that is, do not use 1st, 2nd, 12th, and so on.
Microsoft style
The line wraps at the eighty-first column.
Not Microsoft style
The line wraps at the 81st column.
Do not use ordinal numbers for dates.
Microsoft style
The meeting is scheduled for April 1.
Not Microsoft style
The meeting is scheduled for April 1st.
Do not add ly, as in firstly and secondly.
In general, use commas in numbers that have four or more digits, regardless of how the numbers appear in the interface. When designating years and baud, however, use commas only when the number has five or more digits.
Do not use commas in page numbers, addresses, and decimal fractions.
Microsoft style
1,024 bytes
page 1091
1,093 pages
1.06377 units
2500 B.C.
10,000 B.C.
15601 Northeast 40th Street
Not Microsoft style
1024 bytes
page 1,091
1093 pages
1.063,77 units
2,500 B.C.
10000 B.C.
9,600 baud
15,601 Northeast 40th Street
Use from and through to describe inclusive ranges of numbers most accurately, except in a range of pages, where an en dash is preferred. Where space is a problem, as in tables and online material, use an en dash to separate ranges of numbers. You can use hyphens to indicate page ranges in an index if you need to conserve space.
Do not use from before a range indicated by an en dash. Do not use between and and to describe an inclusive range of numbers because it can be ambiguous. For more information, also see Dates, Dashes (Chapter 9), less vs. fewer vs. under (Appendix A), Measurements and units of measure, more than vs. over (Appendix A).
Microsoft style
from 9 through 17
2008–2010
pages 112–120
Not Microsoft style
between 9 and 17
from 2008–2010