Metric Conversions

The metric system is based on the powers of ten. Unlike the US Standard system, converting numbers in metric is essentially as simple as sliding a decimal point left or right. Consider the follow sets of conversion charts.

US ConversionsMetric Conversions
1 foot = 12 inches1 mile = 5280 feet1 centimeter = 10 millimeters1 meter = 10 decimeters
1 yard = 3 feet1 mile = 8 furlongs1 kilometer = 1000 meters1 meter = 1000 millimeters
1 gallon = 4 quarts1 quart = 2 pints1 kiloliter = 1000 liters1 liter = 1000 milliliters
1 pound = 16 ounces1 ton = 2000 pounds1 kilogram = 1000 grams1 gram = 1000 milligrams

There are many other prefixes in the metric system that allow for much larger (like tera-) and much smaller (like pico-) numbers.

For basic metric conversions, we can use a mnemonic khD1dcm to convert through seven orders of magnitude. We use the phrase "King Hector Drank One delicious chocolate milk" to remember the order.

The Basic Metric Chart

PhraseKingHectorDrankOnedeliciouschocolatemilk
Prefixk-h-D--d-c-m-
Namekilo-hecto-deca-[base unit]deci-centi-milli-

The base unit determines what type of quantity you are measuring. You could measure length/distance, volume, time, energy, and many other things. Most base units have an abbreviation that is written after the metric prefix. So cm would be centimeters and kg would be kilogram. The letter on the right side of the unit is the base unit. Pay attention to the capitalization of the letters! NOTE: If you ever have just one letter for the unit, then it's already the base unit! So, g is grams and m is meters (not millimeters). The BEST PART about this whole thing is that it doesn't matter what your base unit it, the conversion process works the same way every time!

Some Metric Base Units

Quantity Being MeasuredBase Unit NameBase Unit Abbreviation
distance/length/heightmeterm
mass*gramg
volumeliterl
energyJouleJ
forceNewtonN
timesecondss
*Note: Scientists use the SI system, which is almost identical to the metric system. The biggest difference to be aware of is that the SI unit for mass is the kilogram, but the base unit of mass in metric is the gram.

Perform a Metric Conversion

  1. What unit are you starting from? Find it on the chart.
  2. What unit are you converting to? Find it on the chart.
  3. Count the number of columns you have to move from start to finish.
  4. Pay attention to the direction you have to move (left or right).
  5. Find the decimal place of the number you are converting.
  6. Move the decimal in the same direction, the same number of spaces that you moved on the chart.
  7. Add extra zeroes if needed.
  8. ALWAYS rewrite the new value and ALWAYS include the new unit.

Practice Conversions

  1. Convert 32.5 cg to g.
    1. Find cg on the chart.
    2. Find g [base unit] on the chart.
    3. Count the number of columns you need to move (it's 2 steps away).
    4. Make mote of the direction you moved (we went to the left).
    5. Find the decimal in the number you're converting (between 2 and 5).
    6. Move it the necessary number of columns in the correct direction (2 steps left in this case).
    Answer: 0.325 g

  2. Convert 52 hm to dm
    1. Find hm on the chart.
    2. Find dm on the chart. (Be careful! You want deci-, not deca-.)
    3. Count the number of columns you need to move (it's 3 steps away).
    4. Make mote of the direction you moved (we went to the right).
    5. Find the decimal in the number you're converting. (There isn't one, so it's to the right of the 2.)
    6. Move it the necessary number of columns in the correct direction (3 steps right in this case).
    7. We moved to the right where there aren't any numbers, so add some zeros as placeholders.
    Answer: 52000 dm

  3. Convert 0.22 cm to m
    1. Find cm on the chart.
    2. Find m on the chart. (Be careful! It's just 1 letter, so it's the [base unit], not milli-)
    3. Count the number of columns you need to move (it's 2 steps away).
    4. Make mote of the direction you moved (we went to the left).
    5. Find the decimal in the number you're converting. (It's between 0 and 2.)
    6. Move it the necessary number of columns in the correct direction (2 steps left in this case).
    7. We moved to the left where there aren't any numbers, so add some zeros as placeholders.
    Answer: 0.0022 m