Some of the content of this guide was modeled after a guide originally created by Openstax and has been adapted for the GPRC Learning Commons in September 2020. This work is licensed under a Creative Commons BY NC SA 4.0 International License.
Base Units
Following are seven base units used in the metric system:
Table 1: Base Units
Property | Unit | Symbol |
Amount of substance | mole | mol |
Electric current | ampere | amp |
Length | meter | m |
Luminous intensity | candela | cd |
Mass | kilogram | kg |
Temperature | kelvin | K |
Time | second | s |
Metric-Metric Conversions
Conversion factors for the metric system can be determined from prefixes added to -meter. Some of the common prefixes are given below.
Prefix | Symbol | Factor |
---|---|---|
femto- | f | 10^{-15} |
pico- | p | 10^{-12} |
nano- | n | 10^{-9} |
micro- | µ | 10^{-6} |
milli- | m | 10^{-3} |
centi- | c | 10^{-2} |
deci- | d | 10^{-1} |
Base unit | 10^{0} | |
deca- | D | 10^{1} |
hecto- | h | 10^{2} |
kilo- | k | 10^{3} |
mega- | M | 10^{6} |
giga- | G | 10^{9} |
Example I
Convert 12.52 L to mL
To go from L to mL, you have to move three times to the left. Therefore, move the decimal three times to the right.
Method 1
Moving the decimal three places to the right gives:
Method 2
SInce you moved three spaces to the left to get to ml on the diagram divide the value by ten to the power of minus three (10^{-3}).
Have questions about how the ten to the power of three became positive? Check out this guide for more details.
Converting Units Using Conversion Factor
Units of length in the metric system | Units of weight in the metric system | Units of volume in the metric system |
1,000 millimeters (mm) = 1 meter 100 centimeters (cm) = 1 meter 10 decimeters (dm) = 1 meter 1 dekameter (dam) = 10 meters 1 hectometer (hm) = 100 meters 1 kilometer (km) = 1000 meters |
1 gram = 1,000 milligrams (mg) 1 gram = 100 centigrams (cg) 1 kilogram (kg) = 1,000 grams 1 metric ton (t) = 1,000 kilograms |
1 cc = 1 cm^{3} 1 milliliter (mL) = 1 cm^{3} 1 liter (L) = 1,000 millimeters (mL) 1 hectoliter (hL) = 100 liters (L) 1 kiloliter (kL) = 1,000 liters (L) |
Example 1
Convert 42.50 m to km
Step 1 : Write the conversion factor from the table above.
1 kilometer (km) = 1000 meters (m)
Step 2 : Write the conversion factor as a ratio.
Since we are converting meters to kilometers, write the km on the top and m on the bottom, as shown below:
Step 3: Multiply 42.50m by the above ratio.
Then the answer becomes 0.04250 km with four significant digits.
** Notice how the "m" on the top and the "m" at the bottom cancel out to give "km" as the final unit, as seen below:
A unit conversion calculator can be used to verify your answers.
Study tips for unit conversion
Want to check your understanding? Try our online Quiz!