Living the in the US (or Liberia or Burma) you may find the premise of base 10 units confusing or frightening. But don't worry, our metric prefix calculator can help you make sense of your measurements and convert them to other magnitudes.

    Not that all metric units have had it easy. The underpinnings of this system of standards, which make research and science easier to share across languages and cultures, didn't happen all at once.

    This article goes through the most commonly asked questions about the formation, definitions, and uses of metric prefixes and units.


    What are metric prefixes?

    Metric prefixes explain a factorial or dimensional expansion of a base unit. Some examples are the prefixes "kilo," "mega," and "giga."

    Rather than write out a number with a lot of zeroes before or after the number, it is easier to use a word (or its notation) to explain the measurement.

    What are the base units of metric prefixes?

    Established in 1875 were base units. Previously only the ideas of length and mass existed with the meter and the kilogram. After several revisions, the units of length, mass, and time were codified.

    In 1901 electromagnetic units were added. At the current time, we had six base units. These include the previous four and also units for temperature and luminosity.

    The final basic unit for quantity of particles for measuring and explaining chemical substance was added too.

    That leaves us with the following as the standard base units that we can attach metric prefixes to:

    • Length - Meter (m)
    • Mass - kilogram (kg)
    • Time - second (s)
    • Electromagnetism - Ampere (amp)
    • Temperature - Kelvin (K)
    • Luminosity - candela (cd)
    • Chemical Substance - Mole (mol)

    What do the metric prefixes mean?

    Each base unit can get further defined by the addition of prefixes.

    With some exceptions for weird lettering, the prefix gets attached to the front of a unit to create a complex metric unit. For example, a kilometer is meter and the prefix "kilo." One kilometer would then equal 1000 meters.

    Note: The kilogram is the basic unit for mass but, as you already notice, it is 1000 grams (hence, kilo - gram).

    Metric Prefixes Table

    Prefixes listed here are for base 10 explanations. When working with hexadecimal or octal, the same prefix names are used to indicate orders of magnitude.

    The prefixes grow by a quantity of 3 (which we call magnitudes) over the base unit. Consider the way we talk about million (1,000,000) versus thousand (1,000) and you see how the 3 zeros are implied as the number stacks up.

    It makes sense to use a calculator to convert these numbers quickly if you have to go through a lot of translations.

    Why were metric prefixes created?

    Work on standardizations of units started in the early 19th century. While standardized units work well for explaining precise concepts for purposes of research and science, they actually started with money in mind.

    Nobody wants to receive a hogshead of flour from a trade ship only to find out that it has arrived in bushels. Most systems of measurement started with some real-world measurement that becomes somewhat standardized.

    Not only that, but each unit of measurement needs to have some bearing on the others. Consider the idea of volume. A cubic meter of air represents a size and a weight (or length and mass to be more specific).

    To this end, the Treaty of the Metre convened in Paris May 20, 1875, and seventeen nations signed into agreement the International Bureau of Weights and Measures (BIPM). This created a set of physical objects that were the basis for the standard units (often simplified as SI) and also what measurements existed.

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