So I am building a Hexapod and want to use SG90 servos. They are rated up to 1.8 kg/cm but if possible I want to keep it under 1.5 kg/cm.

I would like to know how to calculate the torque of each servo at a time.

Here is a diagram of my design, assume that 3 (2&1) out of 6 legs are in contact with the ground at a time and assume for simplicity that the total weight is 10N - I am not sure what the final weight will be yet

Each leg has 2DoF, and therefore 2 servos as shown in the diagram below