Oxygen accounts for 23.1% of Earth's atmosphere by weight (or 1.189 quadrillion metric tons).
It also accounts for 88.8% of Earth's oceans by weight (1.201 quintillion metric tons).
And finally, Oxygen takes up 49.2% of Earth's crust by weight (about 11.7 quintillion metric tons).
Thus, the Earth's crust hoards 90% of all the oxygen on Earth, with the oceans taking most of the remaining 10% - leaving just one part in 10,000 for the atmosphere.
The total mass of Oxygen on and in the Earth is about 12.9 quintillion metric tons.