"Ten items or less" is on supermarket signs everywhere, and it's one of the best-known grammar debates in English. Here's the rule, and when it bends.

The short answer #

  • Fewer is for things you can count: fewer emails, fewer mistakes, fewer people.
  • Less is for things you can't count (amounts): less time, less water, less stress.

The counting test #

Ask yourself: can I put a number in front of it?

  • three emails ✓ → fewer emails
  • three waters ✗ → less water

Examples #

  • I make fewer typos when I slow down.
  • This version uses less battery.
  • There were fewer than 20 people at the meeting.
  • I have less free time this month.

The exceptions #

Use less with numbers that describe an amount of time, money, distance, or weight, because you think of them as a single quantity:

  • It took less than 10 minutes.
  • It costs less than $5.
  • We live less than two miles away.

Less than is also normal with percentages and with one: less than 30%, one less thing to worry about.

Common mistakes #

Wrong Right
Less people came this year. Fewer people came this year.
I need fewer sugar. I need less sugar.
Less mistakes Fewer mistakes

Check it automatically #

AI Grammar Checker knows which nouns are countable and suggests fewer or less where it matters.