Also see the Dashes section of BHGStylebook.com.
Hyphens cause problems and confusion out of proportion to their size. Contributing to that confusion is a lack of consensus among experts on the proper use of hyphens. The following rules should eliminate much of the confusion, as well as the misspellings that often occur as a result of incorrect hyphen use.
Use a hyphen for a verb of two or more words that form a single thought.
She double-spaced the copy.
Use a hyphen for a one-thought compound modifier placed before the noun it modifies.
a three-piece suit
a factory-built home
Use a hyphen for a one-thought compound modifier of more than two words placed before the noun it modifies.
a fool-the-eye design
an up-to-date design
11/2-story-house (not story-and-a-half-house)
Multiple hyphens make it difficult for readers. Unless it’s needed for effect, look for ways to rewrite for clarity and readability as well as simplicity.
An out-of-India-by-way-of-Oregon garden … might become
This Oregon garden’s style comes straight out of India.
The singing sensation-turned-interior-designer … might become
Once a singing sensation, she turned her attention to interior design.
Use a hyphen when a number and a noun form a one-thought modifier before another noun.
Hyphenate compound adjectives that consist of a noun plus an adjective, such as tax-exempt, machine-washable, or ice-cold, whether they are before or after the verb.
The energy-efficient glass has a high R-value.
The coating makes the glass energy-efficient.
The weather-resistant finish makes the furniture durable.
The siding is maintenance-free.
Hyphenate “well” compounds before a noun. Hyphenate after a noun if preceded by a linking verb.
The well-known speaker came to town.
The well-organized team completed the task quickly.
The team was well-organized.
She seems well-spoken.
Use a hyphen when “odd” or “plus” is added to a cardinal number.
30-odd years ago
Use a regular hyphen in phone numbers and 9-digit ZIP codes.
Use a hyphen for spelled-out fractions.
Flowers are grown in two-thirds of the garden.
Use an en dash (option + hyphen) to indicate a range.
a 30–40 percent increase
75–90 percent of homeowners
Some adjectives are always hyphenated, regardless of their position in a sentence. (Consult a dictionary or the Word List.)
Though good-looking, the project was time-consuming.
SIM style: Hyphenate “-lover” compounds to eliminate ambiguity. (added 8.5.13)
Omit a hyphen in a compound modifier that contains an adverb ending in ly.
a hastily executed project
Omit a hyphen in dual heritage terms (employed only when relevant to the heritage of an American person). In choosing which term to use, defer to the individual’s preference or country of origin. (added 4.9.21)
Omit a hyphen with a proper noun used as an adjective.
a Park Avenue address
a Supreme Court decision
Omit a hyphen when a well-established compound noun functions as an adjective.
acoustical tile ceiling
art supply stores
bay window curtains
crafts supply stores
dining room table
fat quarter bundle
flea market find
folk art collection
food preparation area
front yard garden
glass block wall
grand prize winner
home center product
home improvement loan
home office space
intensive care unit
life insurance agent
microwave oven shelf
plastic canvas crafts
sewing machine needle
sliding glass door
sour cream sauce
thrift store find
wall covering design
weight loss solution
whole grain bread
whole wheat rolls
However, when a well-established compound noun is combined with a participle to form a one-thought modifier, a hyphen is required before the participle. These open compound modifiers are often proper noun forms.
Art Deco-style chair
ice cream-covered counters
New York-based designer
Pulitzer Prize-winning play
Queen Anne-style house
Never hyphenate a word at the end of a page; try to avoid hyphenating the last word in a column.