Torque = Weight x Distance to Center of Gravity x Cosine(Angle)

(If weight is evenly distributed, distance to CG is Length/2)

How do you calculate torque for a hinge?

It's important to calculate the necessary hinge torque to understand the ideal rotational resistance for your application. Once you've calculated torque using the maximum holding angle, center of gravity and weight, you're ready to shop for friction hinge solutions.