Scan area flight time calculator

Hi - I know there are a lot of variables (equipment, altitude, temperature, wind, battery age, overlap, shape of scan area, etc.) but I was just wondering if people used any “back of the envelope” methods to calculate the amount of area they can cover with a 2D or 3D scan. Thanks, any guidance would be greatly appreciated.

For example, a basic rule of thumb I am currently using is that at max altitude (399’) I can almost always complete a 20 acre “squarish” parcel with one battery with my Mavic Pro 2.