How is the Mass of Earth Calculated?
There are multiple ways to calculate the mass of earth. Assuming that your question is from the chapter Gravitation, I explain that here.
Knowing the radius of earth and the value of acceleration due to gravity, we can calculate the mass of earth.
If we put g = 9.8 ms-2 R = 6400000 m and G = 6.67 x 10-11 Nm2 kg-2
We will get M=6.0 x 1024 kg