according to the definition of the Q-factor of damping, it is given by:

$Q = 2\pi\frac{Energy \; Stored}{ Energy \;Dissipated \; per \;cycle }$


Q = 1⁄2 --> Critical damping 

Q > ​1⁄2 --> Over damped 

Q < 1⁄2 --> Under damped


In my experiment, I am finding the condition for critical damping but when I calculate the Q factor I am getting very high values, even if the oscillations are underdamped.  The data I am recording is the initial angle of the pendulum and the angle after 1 oscillation. 


Is there any other formula to calculate the Q factor of damping in a pendulum based on the angle of the pendulum and Q factor.