Metric Prefixes megaConverter #34


The real benefit of the metric system is that most units in a particular type of measurement are multiples of 10 of the other units of the same measurement. For instance, a kilogram is merely 1000 grams, a kilometer is 1000 meters, a centimeter is .01 meters, a hectare is 100 ares, a milliliter is .001 liters. For larger or smaller numbers it is handy to add prefixes to the basic unit to generate larger or smaller units. The basic unit of mass is the gram, the units of volume are the liter or the stere, the unit of length is the meter, and the units of area are the are or barn. There are many other units for other physical types as well and all these units can use the same prefixes. A few types of measurements have two or more separately defined units that, while still differing only by factors of ten, have separate names. Force has Dynes and Newtons, while energy has Ergs and Joules. There are others.

Many times, when units of very large or very small size are not commonly referred to in every day use, the standard way to refer to them is as numbers of more common units, such as millions of kilometers instead of Gigameters, or as trillionths of a liter rather than picoliters. However, very large and very small prefixes do exist and are used in fields where those sizes of units are more common. As computer technology progresses, we now speak of Terabytes of disk storage and picoseconds per operation. Astronomy has uses for very large distances and volumes and as humans expand into outer space Petameters and Yottasteres may come into more common usage. Atomic physicists might speak of yoctosteres when referring to subatomic particle volumes.

One standard for metric prefixes that is often used but also often ignored is that prefixes for a million or greater are capitalized and others are not capitalized. You should attempt to capitalize Mega units and above. Deca, the prefix for 10 is also usually capitalized. The reason for this is so that abreviations can be distinguished. Thus 'Mg' is a Megagram and 'mg' is a milligram. Similarly 'Dl' is a Decaliter and 'dl' is a deciliter. Micro units are typically not abreviated or abreviated as mic. This is to avoid confusion with milli units. An exception is the micrometer which has come to be called a micron.

* Much of our written history still refers to things in common units. The Bible does not refer to meters or kilograms, but to cubits and stadia, or shekels and drachma. Wouldn't it be nice to know what they were talking about way back then? Now you can use megaConverter! For a more complete listing of ancient, foreign, and obsolete measures, download our 'megaSpreadsheet' of conversions in MS Excel format.