Grammarama

Amount vs. Number

One uses the word amount to refer to the quantity of something that is measured as a whole—not by its individual contents—while number, as the name suggests, refers to something that has a clearly defined count associated with it. There are certainly a definite number of salt grains in any batch of salt, but to count all of them would be an exhausting and pointless task. Instead, we refer to the overall amount of salt. The individual components of liquids are even less clearly defined than grains of salt. We could measure the number of cups of water, but we would need to look to the level of atoms or molecules to measure water’s contents individually.

In addition, different words are used depending on whether one is describing amounts or numbers of things. The first word in the following pairs is associated with amount, and the second word is associated with number.

Little – Few
Less – Fewer
Much – Many

Examples:

The amount of food wasted in the United States each day is appalling.
The number of pounds of food wasted in the United States each day is appalling.
You offered me little recourse.
You offered me few alternatives.
Americans spend less money each year on foreign aid than on diet products.
Americans spend fewer dollars each year on foreign aid than on diet products.
He has too much free time on his hands.
He has too many hours of free time on his hands.

As you can see, it’s often quite simple to switch between describing things in terms of amounts and numbers, but one form usually sounds better and/or makes more intuitive sense.