Less Then or Less Than – Which Is Correct? (Examples)

Many people confuse “less then” and “less than” because the words then and than sound similar. This common mistake appears in emails, schoolwork, and everyday writing.The correct phrase is “less than.” It is used to compare numbers, amounts, time, or quantities. 

“Less then” is almost always a grammar mistake unless then is being used to talk about time.In this guide, you will learn why “less than” is correct, when then should be used instead, and how to avoid this common error. Easy examples will help you remember the difference every time.

Less Then or Less Than – Which Is Correct?

Only one of these phrases exists in proper English grammar, and that’s “less than.” It’s used to compare two things — numbers, amounts, time, or objects — and show that one is smaller or fewer than the other.

“Less then” doesn’t hold up grammatically because “then” has nothing to do with comparison. It’s a time-related word, not a connector for measuring differences. Pairing it with “less” creates a sentence that simply doesn’t make logical sense.

Here’s the distinction in a nutshell:

Phrase	Correct?	Function
Less than	✅ Yes	Compares quantity, amount, or number
Less then	❌ No	Mixes comparison with a time reference

Once you understand that “than” belongs to comparisons and “then” belongs to time or sequence, the confusion mostly disappears.

Less Then

“Less then” shows up often in casual texts, emails, and even published content, but it’s never grammatically acceptable. The issue comes down to one small letter — “e” instead of “a” — yet that single swap changes the entire function of the word.

“Then” is an adverb used to describe time or sequence. It tells readers when something happens, not how two things measure up against each other. Some common (correct) uses of “then” include:

• First we’ll finish dinner, then watch a movie.
• I lived in Chicago back then.
• If it rains, then we’ll reschedule the trip.

None of these relate to size, amount, or comparison — which is exactly why “then” can’t logically attach to “less.”

Common reasons people write “less then” by mistake:

1. Similar pronunciation — in fast or casual speech, “than” and “then” can sound nearly identical.
2. Autocorrect or typing speed — the brain often types the more frequently used “then” out of habit.
3. Limited exposure to the grammar rule — many learners were never taught the comparison-versus-time distinction directly.

Whatever the reason, “less then” should be corrected wherever it appears — in essays, emails, social posts, or professional documents.

Less Than

“Less than” is the grammatically correct phrase, and it works as a comparison tool. “Than” functions as a conjunction that links two parts of a sentence to show a difference in size, amount, value, or degree.

Whenever you’re measuring something against something else — and one side comes up smaller — “less than” is the phrase you want.

Take a look at these example sentences:

• She has less than ten dollars left in her wallet.
• This recipe takes less than thirty minutes to prepare.
• The new laptop weighs less than the older model.
• We finished the project in less than a week.
• His score was less than what he expected.

Notice how each sentence sets up a comparison — money, time, weight, or performance — and “less than” connects the two sides smoothly.

Quick Comparison Table

Sentence	Correct Version	Why
I have less then five minutes.	I have less than five minutes.	Comparing time
She earns less then her coworker.	She earns less than her coworker.	Comparing income
This box weighs less then the other one.	This box weighs less than the other one.	Comparing weight
It cost less then I thought.	It cost less than I thought.	Comparing expectation vs. reality

A simple trick to remember the rule: “than” rhymes with “comparison,” and “then” rhymes with “when.” If your sentence is answering “compared to what?”, you need “than.” If it’s answering “at what point in time?”, you need “then.”

Which Is Used the Most?

There’s no contest here — “less than” is used overwhelmingly more often than “less then” in published, professional, and everyday writing. Style guides, grammar resources, and major publications consistently use “less than” because it’s the only version that’s actually correct.

“Less then” appears almost exclusively as a typo or an honest mistake, not as an accepted alternative. You won’t find it in dictionaries, grammar references, or edited content, because there’s no scenario where it’s the intended phrase.

In both UK and US English, the rule stays the same — there’s no regional variation that makes “less then” acceptable in one dialect and not the other. If you’re writing for an international audience, you can use “less than” with full confidence anywhere in the English-speaking world.

Final Thoughts

The takeaway is simple: “less than” is correct, and “less then” is not. “Than” handles comparisons of amount, number, or degree, while “then” deals strictly with time and sequence. Since the two words serve completely different grammatical purposes, they’re never interchangeable.

The easiest way to avoid this mistake going forward is to ask yourself one question before you type: Am I comparing two things, or talking about timing? If you’re comparing, “than” is your word. Once this small check becomes second nature, you’ll stop making the mix-up altogether — in emails, school assignments, professional reports, and everyday conversations alike.

FAQs

What is the correct phrase, Less Then or Less Than?

“Less than” is the correct phrase. It’s used to compare numbers, amounts, or quantities, while “less then” is grammatically incorrect.

Why is Less Than Wrong in English Grammar?

This phrasing mixes up two different words — “then” refers to time, not comparison, so it can never correctly follow “less” in a comparative sentence.

How do I use Less Than in a sentence?

Use it whenever comparing amounts or numbers, such as: “This shirt costs less than twenty dollars.”

Is Less Than used more often than Less Then?

Yes, by a huge margin. “Less than” is the only grammatically accepted form, while “less then” is simply a common typo.

Can I use Less Then in informal writing or messages?

No — even in casual texts or messages, “less then” is incorrect and should be replaced with “less than” for clarity.