How to Do Metric Conversions

Despite the United States’ failed attempt to convert to the metric system, there are plenty of reasons why we need to understand it.

Whether you need to help your kid with their math homework, you’re trying to convert a recipe, there are sure to be times when you find yourself needing to understand how to do metric conversions.

Luckily, this is much easier than you might think!  Stick with us as we go through the basics of converting metric units, and you’ll feel like a pro in no time!

The Metric System 101

Once you understand the basics of how the metric system works, you’ll see just how easy metric conversions are to do. First, it’s important to understand that there are three types of metric units:

• Liters (L) – this measures volume (ex. 2-liter bottle of Mountain Dew)
• Grams (g) – this measures mass (ex. 500 grams of flour)
• Meters (m) – this measures length (ex. 1.5 meters tall)

All of these units are base don powers of 10, which is part of what makes the metric system so easy!

The primary units used in the metric system are as follows:

• Kilo-
• Hecto-
• Deka-
• Deci-
• Centi-
• Milli-
• Micro-

This might seem confusing at first, but stick with us and we promise you’ll get it.

First, we’ll start with a base unit, which would be 1 liter, gram, or meter. We’ll use grams for this example.

The first three units listed above are all larger than one. A dekagram is 10x bigger than a gram. A hectogram is 100 x larger, and a kilogram is 1,000 x larger.

The final four are all smaller than a gram. A decigram is 10 x smaller, a centigram is 100 x smaller, a milligram is 1,000 x smaller, and a microgram is 1,000,000 smaller.

How to Do Metric Conversions – The Easy Way!

If this is starting to concern, you, don’t worry! You can always pull up online converters that will quickly do the math for you. But this isn’t always convenient.

Check out these three metric conversion hacks and you’ll be able to quickly do it in your head without having to pull out your phone or hop on the computer.

1. Memorize the Units in Order

A handy way to remember the order is to use this memory trick: “King Henry Doesn’t Usually Drink Chocolate Milk.” The “U” stands for the base unit (liter, gram, or unit).

When you’re first learning how to convert metric units, draw a straight horizontal line ono a piece of paper and write down the prefixes in order from largest to smallest. It will look like this:

Kilo – Hecto – Deca – (UNIT) – Deci – Centi – Milli

Everything to the left of “Unit” is larger and everything to the right is smaller. This is a good visual reference.

2. Move Your Decimals

The next thing you’ll want to do is figure out what you’re converting from and to. For example, let’s assume you’re converting a kilometer into a centimeter. Using the reference above, you can see that “centi” is 5 movements to the right from “kilo”

Kilo → (1) Hecto → (2) Deca → (3) UNIT → (4) Deci → (5) Centi – Milli

Just move your decimal point over that many places, adding zeros where needed, and you have your answer.

So, your math would look like this:

• 0 kilometers
• 10.0
• 100.0
• 1,000.0
• 10,000.0
• 100,000.0 — There are 100,000 centimeters in 1 kilometer.

You can also do this in reverse. For this example, let’s look at converting a millimeter into meters. Using the same system above, you would simply start at “milli” and move your decimal to the left, adding a zero where necessary.

Kilo — Hecto — Deca — (UNIT) (3) ← Deci (2) ←  Centi (1) ← Milli

In this example, the math would look like this:

• 1 millimeter
• 0.1 centimeter
• 0.01 decimeter
• 0.001 meter

So, there are 0.001 meters in 1 millimeter.

3. Option 2: Scale by Powers of 10

If you’re not a visual person, you may want to forego the method above and instead use multiplication or division. The concept is relatively similar and you can still use the chart for reference if this helps. 

For example, using the first example above (kilometers to centimeters), you’ll remember that we moved five units to the right. Moving to the right equates to multiplying, so you would write the equation as ten to the fifth power (105) or:

10 x 10 x 10 x 10 x 10 = 100,000

As you can see, this brings you to the same answer. There are 100,000 centimeters in a kilometer.

Now, let’s apply this to the second example. When you are moving in the other direction or converting from a small unit to a larger unit, you’ll divide by a power of 10.

In the example where we tried to determine how many liters were in a millimeter, you’ll recall that we moved three units to the left. Using this method, you would multiply your measurement by 10 to the power of negative three, or 10-3. This results in the same answer, which is that there are 0.001 meters in a millimeter.

Personally, we find this method to be far more confusing and prefer simply moving the decimal instead. And, remember, if all of this makes your head spin, you can always just go online and use a converter!

Explore More Great Tips and Everyday Life Hacks

That’s it! Now you know how to do metric conversions! It’s easy, isn’t it?

Our site has all kinds of articles just like this that will teach you everyday life hacks. Spend some time browsing through – you never know what you’ll find!