Surface area calculation of droplet in Paraview
 

I have an OpenFOAM 3D-case. A droplet is initialized inside the computational domain using in .

Now, I want to calculate the surface area of the droplet at several instances of time (lets say 0.1, 0.2). Can anyone please guide me on how can I accomplish this? Few hours digging into the forum and could not find anything specific.

Thanks in advance :)

This is late response.
This is responded in the forum before. FYI:
scalar bubbleSurfArea = gSum( (gradalpha1.internalField() * mesh.V())() );