Amount or Number?

Can you spot the error in the following sentence?

“She couldn’t believe the amount of people waiting in line at Dairy Queen.” 

If you can’t find anything wrong, you’re not alone!  

This sentence should read, “number of people” not “amount of people.”   

Amount vs Number

Although “amount” and “number” both refer to quantity, they aren’t interchangeable. Use “number” when you’re referring to something that can be counted, or numbered.  That’s one way to remember the rule!  So, number of people, number of Super Bowls, number of presidential candidates.   

Use “amount” with things that can’t be counted, or numbered, like space, time, and energy.  So, the amount of energy in the universe, the amount of space in my closet, the amount of time on my hands. 

If you’re talking about a specific unit of energy or time, like a kilowatt or an hour, use “number,” since kilowatts and hours can be counted.  One kilowatt, one hour, etc. 

Some words, like time or space, can be tricky, though, because they have both countable and non-countable definitions.  When you’re talking about a moment in time, use number, as in “the number of times you sent a text message.”  When you’re talking about time in general, use amount, as in “the amount of time it took me to write this post.”   

Here’s a sentence that illustrates the correct use of both amount and number. 

I feel guilty about the amount of ice cream I ate on July 4^th but hope that nobody at the picnic noticed the number of ice cream sandwiches I ate.

So, the next time you’re writing an essay or paper and think about using the word “amount,” make sure it qualifies a non-countable noun!