SI Prefixes Used with Units in Physics, Chemistry and Engineering

Below are shown the prefixes (factors) used with units in physics, chemistry and engineering. The symbol, the name, the corresponding factor as well as an example for each prefix are presented.

Symbol Name Factor Example
y yocto 10-24 2 ym = 2 × 10-24 m = 0.000 000 000 000 000 000 000 002 meters
z zepto 10-21 5 zm = 5 × 10-21 m = 0.000 000 000 000 000 000 005 meters
a atto 10-18 4 am = 4 × 10-18 m = 0.000 000 000 000 000 004 meters
f femto 10-15 5 fm = 5 × 10-15 m = 0.000 000 000 000 005 meters
p pico 10-12 7 pF = 7 × 10-12 F = 0.000 000 000 007 farads
n nano 10-9 5 nm = 5 × 10-9 m = 0.000 000 005 meters
μ micro 10-6 6 μm = 6 × 10-6 m = 0.000 006 meters
m milli 10-3 5 mm = 5 × 10-3 m = 0.005 meters
c centi 10-2 4 cm = 4 × 10-2 m = 0.04 meters
d deci 10-1 6 dm = 6 × 10-1 m = 0.6 meters
da deka 10 2 dam = 2 × 10 m = 20 meters
h hecto 102 5 hl = 5 × 100 l = 500 liters
k kilo 103 1.6 kg = 1.6 × 103 g = 1600 grams
M Mega 106 19 MW = 19 × 106 W = 19 000 000 Watts
G Giga 109 3 GHz = 3 × 109 Hz = 3 000 000 000 Hertz
T Tera 1012 2 TW = 2 × 1012 Watts = 2 000 000 000 000 Watts
P Peta 1015 11 PHz = 3 × 1015 Hz = 11 000 000 000 000 000 Hertz
E Exa 1018 4 Em = 4 × 1018 meters = 2 000 000 000 000 000 000 meters
Z Zeta 1021 12 ZHz = 12 × 1021 Hz = 11 000 000 000 000 000 000 000 Hertz
Y Yota 1024 21 Ym = 21 × 1024 meters = 2 000 000 000 000 000 000 000 000 meters