missing hyphen in 'low cost'

Hyphens bind words that act together as a single modifier before a noun. When the phrase comes before the noun and the words form one idea, add a hyphen (low-cost products). After the noun, or when the first word is an -ly adverb, you usually don't hyphenate.

Below: a compact rule, clear examples (copyable wrong→right pairs), quick rewrite templates, and fast checks you can use immediately.

Quick answer: hyphenate compound modifiers before a noun

Put a hyphen between words that jointly modify a noun when they appear before that noun (low-cost products, well-known author, long-term plan). Don't hyphenate after the noun (the plan is long term) or with an -ly adverb (a highly qualified candidate).

Before a noun: hyphenate compound modifiers (low-cost products).
After a noun (predicate): usually no hyphen (the products are low cost).
-ly adverbs: don't hyphenate with the following adjective (a highly qualified candidate).

Core explanation: why hyphens matter

Hyphens show that multiple words form a single modifying unit. Without them, readers may parse the phrase incorrectly or pause to reinterpret it. Use hyphens when omission creates even a momentary ambiguity; when meaning stays clear, some compounds can be left open depending on style.

Compound modifier = words working together to describe a noun (low-cost, well-known).
Hyphens boost clarity and polish, especially in formal writing.

Examples: common wrong → right pairs (copyable)

Six frequent mistakes you'll encounter; these are safe fixes in most styles.

Wrong: The store offers a wide range of low cost products.
Right: The store offers a wide range of low-cost products.
Wrong: She is a well known actress in Hollywood.
Right: She is a well-known actress in Hollywood.
Work - Wrong: We need a long term plan for Q3. Work -
Right: We need a long-term plan for Q3.
Work - Wrong: A high level overview will help the team. Work -
Right: A high-level overview will help the team.
School - Wrong: The 10 year old student won the contest. School -
Right: The 10-year-old student won the contest.
Casual - Wrong: They went on a 20 mile hike last weekend. Casual -
Right: They went on a 20-mile hike last weekend.

Numbers, ages, and measurements

Hyphenate numeric compounds when they modify a noun. When the phrase follows the noun, no hyphen is needed.

Before a noun: hyphenate (a 5-foot shelf; a 10-year-old student; a 30-minute meeting).
After a noun (predicate): no hyphen (the student is 10 years old; the meeting lasted 30 minutes).
Spelled-out fractions used as modifiers also take hyphens (a two-thirds majority).

Wrong: We scheduled a 30 minute call.
Right: We scheduled a 30-minute call.
Wrong: The 8 year old made a model volcano.
Right: The 8-year-old made a model volcano.
Wrong: They bought a 12 inch pizza.
Right: They bought a 12-inch pizza.

Adverbs and -ly: the common exception

If the first element is an adverb ending in -ly, don't hyphenate (a highly effective plan). The -ly adverb already links to the adjective and doesn't need a hyphen.

No hyphen: adverb (-ly) + adjective (a poorly written essay).
Yes hyphen: non -ly modifier + adjective before a noun (well-known author, old-fashioned style).

Wrong: She handed in a poorly-written essay.
Right: She handed in a poorly written essay.
Wrong: A highly-qualified candidate applied for the job.
Right: A highly qualified candidate applied for the job.
Wrong: A newly-released app caused trouble for testers.
Right: A newly released app caused trouble for testers.

Spacing, en dashes, and small style notes

No spaces around hyphens in compound words. Use an en dash for ranges (1999-2003) or to link elements that already contain hyphens. Different style guides treat some compounds differently-pick one and be consistent.

Hyphen: no spaces (low-cost).
En dash: ranges and complex compounds (1999-2003, or World War II-era depending on style).
Check house style for closed vs. open compounds (email vs e-mail) and apply consistently.

Wrong: low - cost products
Right: low-cost products
Wrong: World War II -era uniforms
Right: World War II-era uniforms
Usage: Ranges: 2001-2005 (use en dash if required by your editor).

Try your own sentence

Test the whole sentence, not just the phrase. Context usually makes the right choice clear: move the phrase after the noun or read it aloud to spot ambiguity.

Real usage and tone: how strict should you be?

Be strict in resumes, reports, academic work, and published copy. In chats and social posts, clarity matters more than perfect hyphenation; readers forgive missing hyphens but not confusing phrasing.

Formal (work/resume/publication) = hyphenate compound modifiers before nouns.
Informal (text/social) = prioritize clarity; hyphenate if omission misleads.
When in doubt and the modifier reads like a single idea, hyphenate.

Work: Resume -
Wrong: Managed full time staff.
Right: Managed full-time staff.
School: Essay -
Wrong: a two year study.
Right: a two-year study.
Casual: Tweet - "Check out our low cost prices!" → acceptable in casual posts, but "low-cost prices" is clearer.

Fix your sentence: checklist and rewrite templates

Checklist: (1) Is the phrase before a noun? (2) Do the words act together to describe that noun? (3) Is the first word an -ly adverb? If yes to 1-2 and no to 3 → hyphenate.

If a hyphen looks awkward, either move the modifier after the noun or rewrite the clause to remove ambiguity.

Template A (hyphenate): [word1]-[word2] + noun → "a low-cost subscription."
Template B (reorder): noun + verb + modifier → "the subscription is low cost."
Template C (clarify): use "that is" or commas → "products that are low cost."

Rewrite:
Original: The store offers low cost items that are well known. Corrected: The store offers low-cost items that are well-known.
Rewrite:
Original: We provide long term support for 10 year old devices. Corrected: We provide long-term support for 10-year-old devices.
Rewrite:
Original: It's a poorly-written, low budget film. Corrected: It's a poorly written, low-budget film.

Memory tricks and quick checks

Two editing heuristics that save time.

BEFORE = hyphen. If the modifier comes BEFORE the noun and forms one idea, hyphenate.
-LY = leave it loose. If the first word ends in -ly, don't hyphenate.
Move-it test: move the modifier after the noun. If the sentence still reads naturally, you can often drop the hyphen; if it becomes awkward, keep the hyphen.

Similar mistakes and other traps to watch for

Watch closed vs. open compounds, confusing hyphens with dashes, and inconsistent choices within a document. Pick a style and stick to it.

Don't use hyphens in place of em dashes or commas.
Check evolving compounds (email and homepage) against your style guide.
Be consistent across headings, body text, and metadata.

Wrong: She runs a small business named 'Green Goods.'
Right: She is a small-business owner who sells eco-friendly products.
Wrong: He sent an e-mail at 8:00.
Right: He sent an email at 8:00. (Or use e-mail if your house style requires it.)
Wrong: The well being of the team matters.
Right: The well-being of the team matters.

FAQ

Do you hyphenate compound adjectives before a noun?

Yes. When two or more words together modify a noun and appear before it, hyphenate them (long-term plan). If they follow the noun (the plan is long term), you normally don't.

Should I hyphenate 'low-cost' in product descriptions?

If 'low-cost' directly modifies a noun (low-cost products), hyphenate. If you use the phrase after a form of be (the products are low cost), you can omit the hyphen.

When do adverbs need hyphens?

Adverbs ending in -ly do not take hyphens with the adjective they modify (a poorly written essay). Only hyphenate if the first word is not an -ly adverb and the compound precedes a noun (well-known author).

How do I hyphenate ages and measurements?

Hyphenate ages and measurements when they appear before a noun (a 5-foot shelf, a 10-year-old student). When they follow the noun or are used predicatively, do not hyphenate (the student is 10 years old).

Can a grammar checker fix missing hyphens automatically?

Many checkers flag likely missing hyphens and suggest corrections, but review suggestions for context and tone. Automated tools catch common cases but may not match your chosen style guide.

Quick edit tip

Run the three-question checklist (before-noun? joint meaning? -ly?) or use the move-it test. When a hyphen reduces even brief ambiguity, add it-especially in formal writing.