Converting between the metric and imperial systems is an essential mathematical skill with many real-world applications. This article will walk through the step-by-step process of converting 0.2 km to mi in a clear, easy-to-understand way, perfect for those with no experience in unit conversions. We’ll also answer some frequently asked questions about kilometer and mile conversions.
Introduction to Length and Distance Conversions
Before jumping into the specifics of converting 0.2 km to miles, it’s helpful to understand what length and distance measurements are. Length refers to a one-dimensional measurement, representing the distance between two points along a line. Some common units used to measure length include:
- Meters (m) and centimeters (cm) in the metric system
- Feet (ft) and inches (in) in the imperial system
Distance is closely related to length but is a more general term. For example, a road sign may indicate the distance to a city in kilometers, which represents the total length you would travel along a route to reach that destination.
Units of length and distance can be converted between one another through mathematical relationships. But to understand how to actually convert units, you need to become familiar with the base units of each measurement system.
The Metric System
The metric system is used nearly everywhere in the world except for the United States. It has several advantages over the imperial system, such as easier unit conversions.
In the metric system, the standard base unit of length and distance is the meter (m). Some other important metric length units are:
- Kilometer (km): 1000 meters
- Centimeter (cm): 1/100th of a meter
- Millimeter (mm): 1/1000th of a meter
So a kilometer represents 1000 meters, making it a larger length unit. A centimeter is 1/100th the size of a meter, making it a smaller unit. Keeping these relationships in mind will help tremendously when making conversions.
The Imperial System
The imperial or US customary system is widely used in the United States for measurement. Its base unit of length is the foot (ft). These are some other key length units in this system:
- Mile: 5280 feet
- Inch: 1/12th of a foot
- Yard: 3 feet
Again, memorizing these unit relationships will help with unit conversions down the road.
Now that you understand the fundamentals of length units in both measurement systems, let’s get back to the main topic – converting 0.2 km to miles.
Converting 0.2 km to Miles Step-By-Step
In this section, we’ll walk through the full process of converting 0.2 km to miles step-by-step. We’ll go slowly and include plenty of explanations so it’s easy to follow as a beginner.
Step 1) Write out the starting unit and value
First, we’ll explicitly write out our starting length value and units:
0.2 kilometers
Writing it out eliminates any ambiguity and helps organize the problem.
Step 2) Memorize the unit conversion
To convert between kilometers (km) and miles (mi), you need to know the following relationship:
1 kilometer = 0.621371 miles
Memorize this simple conversion. You don’t need to memorize where it comes from originally. Just knowing it converts 1 km to 0.62 mi is sufficient to do any km to mi conversion.
Step 3) Set up a fraction with units
Set up the units you have and want to end up with as a fraction:
km
------- = x mi
miWe want to convert starting kilometers into ending miles, so km goes on top and mi goes on bottom.
Step 4) Insert starting value
Plug in the starting 0.2 km value into the fraction:
0.2 km
--------------- = x mi
0.62137 miOn top goes the starting length value (0.2 km). On bottom goes the unit conversion ratio expressing how many miles are in 1 km.
Step 5) Solve the fraction
Solve the fraction by multiplying the numerator and denominator:
0.2 km 0.2
--------------- x ------------ = 0.32137 miles
0.62137 mi 0.62137The kilometers unit cancels out, leaving just miles.
Step 6) Round the answer
Round the answer to an appropriate number of decimal digits. Since we’re converting kilometers, which do not have fractional units, we round to 3 decimal places:
0.2 kilometers = 0.321 miles
And there you have it – we have now converted 0.2 km to 0.321 miles!
Let’s do another quick example to drive the process home. Try converting 0.15 km to miles – pause the video and work it out on your own using the 6 steps before revealing the answer.
Welcome back! Using the exact process we just walked through, here is the conversion:
0.15 km
--------------- = 0.093 miles
0.62137 miSo 0.15 km converts to 0.093 mi.
Frequently Asked Questions
Here are answers to some common questions beginners have about converting 0.2 km to miles:
Q: Why do I need to memorize the 1 km = 0.62137 mi conversion ratio?
A: This conversion factor lets you relate any km value to a mi value. All metric to imperial unit conversions require learning the standard ratio that links one unit to the other. Memorizing this ratio is essential for easily converting between km and mi.
Q: Should I round to a certain number of decimal places when converting km to miles?
A: It’s best practice to round miles to 3 decimal places after a km to mi conversion, since kilometers themselves do not have fractional units. Any digits past 3 decimal places are usually insignificant.
Q: What’s the easiest way to remember the km to miles relationship?
A: An easy way to remember that 1 km is roughly 0.6 miles (0.62137 to be exact) is to note that kilometers are longer distances. So 1 km will be more than half of a mile. Memorizing this general relationship can help the exact 0.62137 ratio stick better when converting units.
Key Takeaways
To summarize the core concepts, here are the key takeaways:
- Length and distance units can be converted by applying a memorized ratio expressing how the units relate.
- To convert km to miles: 1 km equals 0.62137 mi
- Write out starting length and units, set up a fraction with units, plug in values, solve, then round appropriately.
- Kilometers convert to more decimal places in miles since mi can have fractional units.