Enter a value in the From field and use the the dropdown to select the appropriate prefixes from for both the From and To values.
From To
1
Factor
Prefix
Symbol
1015 peta P
1012 tera T
109 giga G
106 mega M
103 kilo k
102 hecto h
101 deka da
     
10-1 deci d
10-2 centi c
10-3 milli m
10-6 micro
10-9 nano n
10-12 pico p
10-15 femto f
10-18 atto a
If it's been a while since you have used exponents or factors of the powers of ten, here's a quick refresher.

For numbers with a positive exponent:
The result is 10 multiplied by itself the number of times of the exponent. For example, 109 = 10 multiplied by itself nine times = 10x10x10x10x10x10x10x10x10 = 1,000,000,000 or one billion.
For numbers with a negative exponent:
The result is 1/10 multiplied by itself the number of times of the positive version of the exponent. For example, 10-3 = 1/10 multiplied by itself three times = 1/10 x 1/10 x 1/10 = .001 or one one-thousandth.