Work out simple pendulum period instantly with clear inputs, formula shown and shareable results.
For small swings the period of a simple pendulum is 2 pi sqrt(L/g), independent of both mass and amplitude - the isochronism Galileo noticed. A one metre pendulum takes 2.006 s per full swing, which is why the seconds pendulum in a grandfather clock is about 0.994 m long.
Period
T = 2 pi sqrt(L / g)
Seconds pendulum
L = g / (4 pi^2) for T = 1 s
No. Mass cancels out, because gravity provides both the restoring force and the inertia in equal measure.
Past about 15 degrees the period grows measurably - roughly 0.5% at 20 degrees and 2% at 40 degrees.