© 2021 Autodesk, Inc.

Table of contents


Use US date formatting.

In body copy, cite the month, day, and year in this format: August 28, 1976. Spell out months, except in tables where space is limited. In tables with limited space, format dates like this: 8/28/1976.

Dates take cardinal numbers. Do not add -nd, -th, -rd, or -st to the end of a date.

NO: Offer ends June 14th.

YES: Offer ends June 14.

Date ranges

When giving a date range, use either an en dash with no space before or after, or use the word pair from and to or between and and. Do not combine the word pairs. Do not use a hyphen or an em dash.

Unfortunately, both en dashes and em dashes render the same on this website, due to the underlying platform. But we swear, they are two different punctuation marks, and they should appear correctly elsewhere.

How to create an en dash

Mac: Option-hyphen

Win: Hold down the Alt key and type 0150, then release the Alt key

How to create an em dash

Mac: Shift-Option-Hyphen

Win: Hold down the Alt key and type 0151, then release the Alt key

In tables and lists, use an en dash to save space

NO: December 1-6, 2018 (hyphen)

NO: December 1—6, 2018 (em dash)

YES: December 1–6, 2018 (en dash)

YES: Dec. 1–6, 2018 (en dash)

In body copy, use one of the recommended word pairs

NO: from December 7–March 7

YES: from December 7 to March 7

YES: between December 7 and March 7

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Temperatures and sizes of angles are expressed in degrees.


In body copy, use numerals, spell out degrees, and specify F or C for Farenheit or Celsius.

Store the product at 10 degrees C.

Store the product at temperatures between 10 and 40 degrees C.

In figures and tables, use the degree symbol (°).

Store the product at 10 °C.


In body copy, use numerals and spell out degree.

Draw a 180-degree arc.

In figures and tables, use the degree symbol (°).

Draw a 180° arc.

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Figure and table captions

Use sentence case.

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Do not use case fractions. Use decimal numerals for measured magnitudes, and use words with other simple fractions.

There is a 1.5-inch variance in the measurement specifications. (not 1⁄2-inch or ½-inch)

This year, three-fourths of newly graduating architects have learned AutoCAD software. (not ¾)

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Spell out units of measure in body copy when the unit is not preceded by a numeral.

You can dimension your drawing by using feet and inches.

A ruler with millimeter measurements will help you be more precise when planning your projects.

When a numeral and a unit of measure form a compound adjective, spell out the unit of measure in body copy unless the abbreviation is more commonly used. For example, spell out inch, pound, second, and hour, but use abbreviations such as mm, km, and MB.

Hyphenate the compound unless the unit of measure is abbreviated.

This parameter provides a 60-second interval between monitoring runs.

The earthquake destroyed a 1,000-pound section of the bridge.

You’ll need a 1 TB hard drive.

The engineering firm used Civil 3D in its feasibility study for a new 69 km highway.

Here are abbreviations for units of measure, their derivatives, and examples of how to use them:

Abbreviation Derivative Usage
cm centimeter The part measures 12 cm.
dpi dots per inch An adequate printer can produce 600 dpi.
g gram The final yield was 7.6 g.
GB gigabyte (1 billion) Users must have 50 GB of disk space.
GMT Greenwich mean time Noon in Seattle is 8 p.m. GMT.
h hour (metric) The image was digitized at 220 cm2/h.
hr. hour (US) The motor burns fuel at 1.2 gal./hr. (Abbreviate only in tables.)
Kbps kilobits per second Data transfer rates can reach 53 Kbps.
K kilobyte (1,024 bits) At 244 K, this is a relatively small file.
kHz kilohertz It’s a fully integrated 24-bit 48 kHz audio subsystem.
km kilometer The firm designed a new 69 km highway.
lb. pound The new laptop is 3 lb. lighter than the old model. (Abbreviate only in tables.)
m meter The ordinary cubicle is 2.5 m on a side.
mm millimeter A4 paper measures 210 by 297 mm.
MB megabyte (1 million) You will need at least 128 MB RAM.
Mbps megabits per second My internet connection’s upload speed is 23.46 Mbps.
MHz megahertz The new 450 MHz processors are standard.
s second The object’s speed is 140 m/s.
TB terabyte (1 trillion) High-capacity data storage is 1 TB or more.
x by This is a 1,280 x 1,024 32-bit color video display adapter.

With US (nonmetric) units of measure, use periods with abbreviations. (Abbreviate US units of measure only in tables.) With metric units of measure, do not use periods.

22 lb.

5 oz.

45 cm

20 mm

Do not add s to an abbreviation to make it plural.

The abbreviation of pounds is lb., not lbs.

The abbreviation of ounces is oz., not ozs.

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In general, spell out numbers zero through nine, and use figures for 10 and higher.

Exceptions that always take figures

Common exceptions include the following:

  • Addresses

7 Park Place

  • Ages (but not for inanimate objects)

the 4-year-old cat

the four-year-old car

  • Cents

8 cents

  • Dollars

Do not include a period and two zeroes when referring to an even dollar figure.


  • Dates

Dates take cardinal numbers.

NO: March 4th

YES: March 4

  • Dimensions

5 foot 2 inches

5-by-9 cell

Note: Do not use case fractions such as ½ or 1⁄2. Use decimal numerals for measured magnitudes, and use words with other simple fractions.)

  • Headings and subheads

3 top trends show green-building technology on the rise

  • Highways

Route 7

  • Millions, billions

6 billion people

  • Percentages

Percent is one word.

1 percent

  • Speed

8 mph

  • Temperatures

2 degrees

2 C

  • Time

Do not include a colon and two zeroes when referring to an even hour.

4 p.m.

  • Years

1999 was a bad year for technology.

Do you remember what happened in 1999?

In 2000, we were all supposed to get jetpacks.

See additional information in other entries on this page.

Exceptions that always take spelled-out numbers

Always spell out numbers that begin a sentence.

NO: 5 AutoCAD users gave feedback on the product.

YES: Five AutoCAD users gave feedback on the product.

Note: Because 3ds Max is a proper noun, you can use it at the beginning of a sentence. But say 3ds Max software…

Commas in numerals

Use commas in figures of four digits or more. See also Measurements.


1,280 x 1,024 32-bit color video display adapter


Use decimals (up to two places) for amounts in the millions and billions that do not require a precise figure.

$3.74 billion


When using ordinals, spell out numbers first through ninth and use figures for 10th and up. Do not turn the endings -nd, -th, -rd, or -st into superscripts (or allow Word to do so).

23rd (not 23d) edition; 22nd (not 22d) edition

17th character

21st century

Plural numbers

Add an s but no apostrophe to a number to make it plural. The same rule applies to decades. Use an apostrophe on a decade only if cutting off the initial figures.

She kept rolling 7s.

the 1980s

the ’80s

See also Prices and Fractions.

*Writing for the web? See additional guidance in the Web Editorial Style Guide.

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Percent, percent symbol

Use the percent symbol (%) in any reference to percent that’s preceded by a numeral. This rule applies to both body copy and headings. Close up the space between the number and the symbol.

We reduced costs by 10%.

Sales rose 5% to 7% last quarter.

Spell out percent when it’s used in copy without a numeral.

We completed the project on time and half a percent under budget.

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Phone numbers

For phone numbers in the United States and Canada, use the format 1-415-555-1212. For extensions, use the form 1-415-555-1212, ext. 33. Use 1 with toll-free numbers, and indicate that the number is toll-free.

Call us toll-free at 1-844-335-4986.

We discourage the use of vanity numbers (such as 1-800-CALLNOW) because they’re not supported on mobile devices. If there’s a strong business reason for using a vanity number, use the numerical version of the phone number first, followed by the vanity number in parentheses.

Call us toll-free at 1-800-225-5669 (1-800-CALLNOW)

International telephone numbers vary widely in format and lengths. We recommend using the local formatting convention for a particular country. For more information, see national conventions for writing telephone numbers.

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Use figures for all amounts.

Nongeotargeted pricing

The first time prices are mentioned in body copy, give them in US dollars (US$) with no space between US and the currency symbol. The US can be omitted in subsequent prices. Use a comma for more than three digits. Omit decimal places for whole numbers (.00) in a price.

For US denominations over four figures, use a comma, as in US$1,000. However, for euro denominations, omit the comma (2000 euros).

The product is priced at US$1,995 ($1,295 for an upgrade).

The mobile apps are $39.95 and $50, respectively.

If mentioning foreign currencies in nongeotargeted body text on the global .com website, spell out as follows:

300 Canadian dollars = C$300 or Can$300

Geotargeted pricing

Geotargeting detects a user’s location and automatically displays location-specific content, such as pricing in the local currency. Geotargeting is implemented on Subscribe pages, Compare pages, and in geotargeted promos. In these cases, there is no need to specify a currency.

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Denote morning or afternoon times as a.m. or p.m., using lowercase letters and periods. Use noon instead of 12 p.m.

Spell out the names of time zones.

Note: Do not capitalize the names of time zones or time designations, except for the proper nouns they contain:

mountain time

eastern time

central time

Pacific time

Greenwich mean time

Always use numerals when referring to time. Delete the decimals :00 unless in a mix.

When giving a time range, use either a hyphen with no space before or after, or use the word pair to and from or between and and. Do not combine the forms.

Call between 6 a.m. and 7 p.m., Pacific time.

Remember that the Boston office is on eastern time. It closes for lunch at noon.

The meeting is scheduled for 9:30 to 11:00 a.m. central time.

The meeting is 9:30-11:00 a.m. central time.

The seminar is 8:30 a.m.-5:00 p.m.

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