Period of a 25 cm Pendulum
A 25 cm pendulum has a period of approximately 1.003 seconds — half the length gives a period reduced by a factor of √2.
How to use this tool
- Enter pendulum length l, gravity g and amplitude θ in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your period (small-angle approx.) and the full breakdown beneath it.
Quarter-metre pendulums are common in mantel clocks and scientific demonstrations requiring roughly 1-second half-swings.
Frequently asked questions
- What is the period of a 1-metre pendulum on Earth?
- Approximately 2.006 seconds, which is why 1-metre pendulums were historically used in grandfather clocks (half-period ≈ 1 s per swing).
- Does mass affect the period?
- No — the small-angle period T = 2π√(L/g) is entirely independent of mass.