Page 289 - Basic Japanese

There are three kinds of counters: “unit counters” (like 3

pounds, 2 hours, 4 years), “class counters” (like 400 head of
cattle, a loaf of bread, 2 sheets of paper), and “ordinal
counters.” Unit counters are used to refer to a quantity of

something divisible like water, time, money, and distance.
Class counters are used for general classes of things that

aren’t ordinarily divisible, like animals, people, pencils, and
books. Ordinal counters are used to specify the place in

some order in time, place, and hierarchy.

Here is a list of some common unit counters:

-guramu …grams

-kiro(guramu) …kilograms

-mētoru …meters

-kiro(mētoru) …kilometers

- …centimeters