The result of your conversion between zettajoule and gigajoule appears here
To convert between Zettajoule and Gigajoule you have to do the following:
First divide 1.0e+21 / 1.0e+09 = 1000000000000.
Then multiply the amount of Zettajoule you want to convert to Gigajoule, use the chart below to guide you.
Symbol: zJ
No description
Symbol: GJ
No description