How to Convert Units of Measurement

Converting units to other units can be a tough ordeal for some elementary and high school students. Even I struggled with the concept when I was studying for my elementary examinations. It was only during high school physics that I've known about the simple way of converting. As you know, physics can be very confusing in terms of units like kgxm/s^2. Hence, I am sharing them to you now to save you of my year-long quandary with unit conversion.

First things first! You MUST MEMORIZE the conversion factors. There's no way we can dispute this step.

Memorizing the conversion factors is essential if you are to convert imperial to metric or vice versa. For example, you want to convert 5 feet 6 inches (imperial) to centimeters (metric). We'll tackle metric system later, it's easier.

We know that 1 foot = 12 inches, and 1 inch = 25.44 millimeters. We need these conversion factors for our problem.

Now, this is our flow: feet-inches > inches > millimeters

5 feet 6 inches has two units. You need to focus on the foot unit first, then just add the second unit later.

               12 inches
 5 feet x  --------------  =  60 inches
                  1 foot    

How did we get inches as the unit of the answer? Simply because in the left side of the equation, the foot units are cancelled out. Actually, it will be you to decide what the numerator and the denominator will be.  If a numerator (in the above case, it's 5 feet, with a default denominator of 1) has a similar term on the denominator, you can cancel them out. In our case, the similar terms are "feet" or "foot."

Another example. You want to convert 72 inches to feet.

                     
72 inches  x   -------------


You know the conversion factor:  1 foot = 12 inches. So since we're dealing with inches as the numerator (72 inches), the denominator of the next item should also be in inches (12 inches).

                     1 foot
72 inches x --------------    =
                   12 inches

The "inches" are cancelled out. The remaining symbols indicate division. And the remaining unit is foot. The answer is 6 feet.

Going back to our previous problem, 5 feet 8 inches = 60 inches + 6 inches = 66 inches.

Since 1 inch = 25.44 mm, then:

                 25.44 mm
66 inches x ------------ =  1679.04 mm
                    1 inch

Let's take it a little further. In converting metric values, you first have to understand the metric conversion table. For the unit of length, the standard value is METER. Any thing longer than a standard value is designated with a Greek prefix. Anything shorter has Latin prefixes. You'll see:

1 meter = 1000000 MICRO meter (um)
1 meter = 1000 MILLI meter (mm)
1 meter = 100 CENTI meter (cm)
1 meter = 10 DECI meter (dm)

10 meters = 1 DEKA meter (dam)
100 meters = 1 HEKTO meter (hm)
1000 meters = 1 KILO meter (km)
1000000 meters = 1 MEGA meter (Mm)

Let's convert 1679.04 mm to kilometer(km), taking note of the placement of numerators and denominators.

                         1 meter             1 kilometer
1679.04 mm x  ----------------- x -----------------  = 0.001679 kilometer
                         1000 mm           1000 meters

Just multiply all values in the numerator, and divide them with all values in the denominator. Cancel out the units until 1 unit is left.

Last example. Convert 12345 feet to kilometer

You have to check your resources and enumerate your conversion factors first. Then our flow would be: feet > inches > centimeters > meters > kilometers

                      12 inches            25.44 mm                1 meter              1 kilometer
12345 feet x ----------------  x ------------------- x ---------------------- x -------------------  =
                      1 foot                   1 inch                   1000 mm               1000 meter


                                                                           3768681.6
= 12345 x 12 x 25.44 / 1000 / 1000 kilometers =  ---------------------- = 3.7686816 km
                                                                             1000000