Online calculation of torsional pendulum oscillation period

The calculation formula of the torsional pendulum oscillation period:
$$
t = 2×pi×sqrt( l I_ 0 / k _t)
$$

In the formula:

Pi = 3.14; t = period [s]; l = spring length [m]; I₀= moment of inertia [kgm²];k
_{t</ Sub> = torsional stiffness [Nm²]}