Metric Prefixes

Multiple of 10      Prefix       Abbrev.   Comment


10**24              yotta        Y 
10**21              zetta        Z
10**18              exa-         E         0.01 exameter is approximately 1 lyr.
10**15              peta-        P          
10**12              tera-        T         The world power use is about 10 Terawatts circa 2003.
10**9               giga-        G         A gigayear (Gyr) is a billion years. 
10**6               mega-        M         Who wants to be a meganaire?
10**3               kilo-        k 
10**2               hecto-       h         Not much used I think.
10**1               deka-        da      
10**0    
10**-1              deci-        d         Only commonly used for decibels I think.
10**-2              centi-       c 
10**-3              milli-       m         Never confuse mJ and MJ.
10**-6              micro-       mu        The Greek mu letter.
10**-9              nano-        n         Nanotechnology is very hot circa 2003. 
10**-12             pico-        p
10**-15             femto-       f
10**-18             atto-        a
10**-21             zepto-       z 
10**-24             yocto-       y 

1. Some of these prefixes are rarely used like atto-. But as technology advances, one often finds them turning up in specialized fields: e.g., nanotechnology uses nano- because supposedly the devices are at the nanometer scale: actually they are often at the hundreds of nanometer scale, but that doesn't sound as grant-attractive.