Does pendulum mass affect the period?

For the ideal simple pendulum model, mass does not affect the period. Length and gravity are the key variables.

When does the small-angle formula work?

It works best at small amplitudes. Above roughly 15 degrees, the period becomes noticeably longer than the small-angle estimate.

It can estimate gravity from measured length and period, but lab accuracy depends on timing, amplitude, pivot friction and length measurement.

Calculate period, frequency, length, gravity or spring parameters for simple, physical and spring pendulum models.

Solve for

Period

String length

Gravity

String length, m

Acceleration, m/s²

Deflection angle, °, optional

Gravity:

The main English intent is a simple pendulum period and length calculator, with gravity and frequency outputs.

T = 2 π \frac{L}{g}

T is period, L pendulum length and g gravitational acceleration.

The small-angle formula is accurate for modest amplitudes; larger angles need a correction.

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

Calculate spring force, spring constant, displacement, elastic potential energy, spring load and equivalent spring stiffness.

Calculate weight from mass and gravity, gravitational force between two bodies, or local gravity at altitude.

Calculate mass moment of inertia for rods, disks, rings, cylinders, spheres, plates, boxes and point masses, with the parallel-axis theorem.