Metric Converter

Learn how to convert metric units by dividing and multiplying by ten with our handy tool: in a few steps, you will learn:

• How to convert metric units;
• The multiples and submultiples of metric units;
• A couple of examples of conversion of metric units;

and much more: jump right into the world of scientific measurements with Omni!

The metric system is the world's most common system of measurement. The system is a relatively recent invention, if compared to the human need to measure things, and dates back to the eighteen century, when the age of enlightenment, in particular in France, brought some reason in the convoluted mess of separated (or not-so-separated) units used back then around Europe, and the world.

The metric system, being simple and intuitive, got adopted quickly by scientists worldwide, superseding feet, pounds, and other relatively weird units. In slightly more than a century, physicists, chemists, and engineers adopted meters, kilograms, and degrees (Celsius): you can still find imperial units in the United States, but even there, they are slowly disappearing.

The push to adopt metric units got a bit stronger when NASA inadvertently destroyed a probe en route to Mars because of a communication error between two components: one of them was talking in imperial units, the other in metric!

To convert metric units, you only need to know a number: $10$! All the units that measure a single quantity (for example, length, mass, time) are connected by multiplication or division by $10$. This saves you a lot of time!

For each quantity, we define a primary unit, representative of the quantity. In a scientific environment, you will always be able to use that primary unit without anyone being phased by it. In the following sections, we will meet the metric units for the most commonly used quantities in science and engineering.

Each quantity, then, can be measured in various multiples and submultiples: to separate and identify them, we use prefixes. Prefixes quickly and uniquely identify the multiple of $10$ to use in the conversion. In the following table, you can see (almost) all the official prefixes used in the metric system. For the submultiples:

And for the multiples:

To convert between metric units, follow these steps:

1. Consider the unit you are converting from: take note of the multiplier.
2. Find the multiplier of the unit you are converting into.
3. Divide the multipliers and multiply the result by the value of the first unit.
4. Change the prefix to the desired one.

To understand how to convert metric units, the easiest thing is to explore how this process works for a specific quantity, let's say, length. The primary unit for the length is the meter. The word meter comes from the Greek métron, "measure". The unit was created in 1793 by French scientists. Back then, the definition was "one ten-millionth of the distance on the Earth's surface from the north pole to the equator, on a line passing through Paris"; now we define the meter as the distance covered by light in $1/299792458$ of a second: talk about scientific improvement!

The submultiples of the meter are, in order of decreasing magnitude:

• The decimeter. $\mathrm{dm}$, equal to $0.1$ meters ($10^{-1}\ \mathrm{m}$);
• The centimeter, $\mathrm{cm}$, equal to $0.01$ meters ($10^{-2}\ \mathrm{m}$); and
• The millimeter, $\mathrm{mm}$, equal to $0.001$ meters ($10^{-3}\ \mathrm{m}$).

Passing in the realm of physics, we meet two other submultiples:

• The micrometer. $\mathrm{μm}$, equal to $0.000001$ meters ($10^{-6}\ \mathrm{m}$);
• The nanometer, $\mathrm{nm}$, equal to $0.000000001$ meters ($10^{-9}\ \mathrm{m}$);

Coming back, in the other direction, we meet:

• The kilometer. $\mathrm{km}$, equal to $1000$ meters ($10^{3}\ \mathrm{m}$);
• The megameter, $\mathrm{Mm}$, equal to $100000$ meters ($10^{6}\ \mathrm{m}$); and
• The gigameter, $\mathrm{Gm}$, equal to $100000000$ meters ($10^{9}\ \mathrm{m}$).

We rarely use the last two of them: the human experience is limited to the kilometer. In the direction of the submultiples, we rarely go smaller than the millimeter: our lives exist in six orders of magnitude!

Let's move outside of metric! Use the other tools of Omni for your conversion needs!

• The conversion calculator;
• The measurement converter;
• The metric to imperial conversion;
• The imperial to metric converter;
• The metric to standard converter;
• The imperial converter; and
• The metric to SAE converter.