The Core Rule: Count Nouns vs. Mass Nouns
The rule for fewer and less depends on whether the noun being modified is countable or uncountable (also called a mass noun).
- Use fewer with count nouns — things you can count individually: chairs, errors, people, days, applications, words.
- Use less with mass (uncountable) nouns — things measured in quantity rather than individual units: water, time, money, effort, traffic, information, advice.
| Fewer (count nouns) | Less (mass nouns) |
|---|---|
| fewer mistakes | less water |
| fewer employees | less time |
| fewer hours | less effort |
| fewer options | less information |
| fewer calories | less sugar |
| fewer words | less noise |
A reliable test: if you can put a number directly before the noun (three mistakes, five employees, ten hours), it is a count noun and takes fewer. If you cannot naturally put a number in front (three traffics? four informations?), it is a mass noun and takes less.
Examples in Context
Fewer — with count nouns:
- The new process produced fewer errors than the old one.
- Fewer than twenty applicants met the minimum requirements.
- She has fewer meetings this week, which allows more time to focus.
- The updated version has fewer steps.
Less — with mass nouns:
- The project required less time than originally estimated.
- With less traffic, the commute took half the usual time.
- The recipe calls for less salt than the original version.
- There is less uncertainty about the timeline now.
The Supermarket Sign Problem
The most famous real-world error with these words appears on supermarket express lane signs: "10 items or less." Since items are countable, the grammatically correct version is "10 items or fewer." This error is so widespread that some style guides have noted it without necessarily endorsing it, and some grammarians consider "items or less" acceptable in informal contexts. In formal writing, however, the distinction should be maintained.
Exceptions and Edge Cases
Time, distance, money, and weight as single quantities. When time, distance, money, or weight is expressed as a total amount — not as individual countable units — less is standard:
- The meeting took less than an hour. (a single duration, not individual hours)
- The store is less than two miles away. (a distance measured as a quantity)
- He earned less than fifty dollars for the job. (a sum treated as a total)
- The package weighs less than five pounds.
If the same nouns are treated as individual units rather than continuous quantities, fewer is appropriate: She worked fewer than five days before quitting (days are countable individual units here).
Percentages and fractions. When a percentage or fraction modifies a mass noun, use less: less than 20% of the budget. When it modifies a count noun, use fewer: fewer than 20% of the respondents.
"One fewer" vs. "one less." With singular count nouns, both are used in practice: one fewer mistake and one less mistake are both common. One fewer follows the strict rule; one less is so natural in English idiom that most style guides accept it.
When "Less" Is Used with Count Nouns
In casual speech, less is often used with count nouns: less people, less cars, less problems. This is widespread in informal English but is considered an error in formal and professional writing. If you are writing for a careful audience, maintain the distinction.
Fewer and Less as Pronouns
Both words can stand alone as pronouns (without a following noun):
- We expected a large turnout, but fewer came than anticipated. (fewer people)
- I used to eat a lot of processed food. Now I eat less. (less food — mass noun implied)
Common Errors
| Incorrect | Correct |
|---|---|
| We have less options than we thought. | We have fewer options than we thought. |
| There were less applicants this year. | There were fewer applicants this year. |
| The report contains less errors. | The report contains fewer errors. |
| He has fewer experience in this area. | He has less experience in this area. |
| She drinks fewer water than recommended. | She drinks less water than recommended. |
Frequently Asked Questions
Is "less than" or "fewer than" correct before a number?
It depends on what follows the number. If the number refers to a count of individual items, use fewer than: fewer than fifty employees, fewer than three attempts. If the number refers to a total amount of time, distance, money, or measurement, use less than: less than two hours, less than a mile, less than $100.
Why does "less" feel more natural than "fewer" in some sentences?
English speakers encounter less far more frequently in daily speech, and the distinction between countable and uncountable nouns is not always obvious. Some count nouns — like calories or items — are often thought of as continuous quantities, which encourages the use of less. For formal writing, apply the count/mass test consistently.
Does it matter in informal writing?
In casual emails, text messages, and social media, few readers will notice or object to less used with count nouns. In professional documents, academic writing, journalism, and published content, the distinction is noticed and expected by informed readers.