meter
The best measurement to use when measuring the width of a house fly is millimeters. This unit is precise enough to capture the small size of the fly, which typically measures about 6 to 7 millimeters in width. Using a ruler or caliper that can measure in millimeters will provide the most accurate results for such a small insect.
In Australia, a metric country, builders use metres and millimetres never centimetres.
In general, we use measuring instruments, but the name depends on what you are measuring.
You can use a measuring jug. Measuring spoons are popular too
Use dry measure measuring cup.
Measuring glasses are used to measure liquids in milliliters. Measuring glasses can be used in recipes, when making drinks, baking or cooking when a certain measurement is required.
the kilometer measurement is best suited
Calculus is a mathematical technique: it is not a unit or tool for measurement.
I am measuring a water in a measuring cup.
Centimeters would be best for measuring a skunk.
inches
There is no such measurement. There is either metric measurement or not. Do you mean "fractions" of inches?