The result of your conversion between zettajoule and Btu appears here
To convert between Zettajoule and Btu you have to do the following:
First divide 1.0e+21 / 1055.0559 = 947817077749150464.
Then multiply the amount of Zettajoule you want to convert to Btu, use the chart below to guide you.
Symbol: zJ
No description
Symbol: Btu
No description