"Fewer choices" or "less choices"? Most people fix this one by ear, and the ear is usually right — until it isn't. The rule is small, the exception is famous, and the difference between the two words is exactly the difference between counting and measuring.
The rule
Fewer goes with countable nouns — things that come in discrete units you can number: fewer emails, fewer errors, fewer meetings. Less goes with mass nouns — substances and abstractions you measure rather than count: less time, less stress, less sugar. The quick test: can you put a number in front of it naturally? Three emails works, so fewer emails; three stresses doesn't, so less stress.
The exception everyone misses
Time, money, and distance take less even though their units are countable. We say "less than two hours," not "fewer than two hours"; "less than $50", not "fewer than $50"; "less than five miles," not "fewer than five miles." The reason is conceptual: we experience those quantities as single amounts on a scale, not as piles of countable things. You don't have two hours the way you have two appointments — you have an amount of time that happens to be measurable in hours.
This is why "fewer than 60 minutes" sounds stiff in marketing copy and wrong in conversation. The exception isn't sloppiness; it's how the language treats measurements.
Twelve examples you can copy
| Countable → fewer | Mass → less |
|---|---|
| fewer mistakes | less confusion |
| fewer customers | less demand |
| fewer calories | less fat |
| fewer steps | less effort |
| fewer features | less complexity |
| fewer pages | less content |
| fewer options | less freedom |
| fewer cars | less traffic |
| fewer ingredients | less sugar |
| fewer emails | less noise |
| fewer plugins | less bloat |
| fewer distractions | less stress |
A useful pattern hides in that table: fewer usually describes the countable symptom of a less-type problem. Fewer steps is the visible result of less effort; fewer emails is what less noise looks like in your inbox.
The checkout-sign debate
"10 items or less" has been on grocery signs for decades, and pedants have been objecting for just as long — items are countable, so the strict form is "10 items or fewer." Both facts are true. Descriptively, the sign phrasing is so universal that most modern style guides tolerate it as an idiom. Prescriptively, formal and professional writing should still use "fewer," because that's where readers notice. The honest summary: the sign will survive; your annual report should still get it right.
A trick that works
If the countable/mass test doesn't settle it in your head, use the collocation test: "few" pairs with fewer, "much" pairs with less. Ask "few what?" or "much what?" — "few complaints" is natural (fewer complaints), "much complaining" is natural (less complaining). Percentages sit on the fence by design: "less than 20% of the budget" (a mass) but "fewer than 20% of voters" (people you can count) — match the word to what the percentage is actually measuring. For more pairs that behave this way, see affect vs. effect and then vs. than — and when you're trimming a draft to a limit, the word counter keeps score while you decide between "fewer words" and "less text."