What formula does this use?

The small-angle approximation T = 2π√(L/g), valid when the swing amplitude is less than about 15 degrees. For larger angles the true period is slightly longer.

Does mass affect the pendulum period?

No. The period of a simple pendulum depends only on its length and local gravity, not the mass of the bob. This is a classic result first observed by Galileo.

What is the standard gravity value?

The international standard is 9.80665 m/s². Actual surface gravity varies from about 9.764 m/s² at the equator to 9.832 m/s² at the poles.

How long must a pendulum be to tick once per second?

A "seconds pendulum" has a half-period of 1 second, meaning T = 2 s. Using T = 2π√(L/g) gives L ≈ 0.9937 m (about 99.4 cm) at standard gravity.

Can I use this for a pendulum on Mars?

Yes. Mars surface gravity is approximately 3.72 m/s². Enter that value in the gravity field to see how much slower a Martian pendulum swings.

What units does this tool support?

Length can be entered in meters, centimeters, or feet — the tool converts automatically. Gravity is always in m/s².

Pendulum Period Calculator

Name: Pendulum Period Calculator
Availability: InStock
Author: Nham Vu

Enter pendulum length and gravity to instantly calculate period, frequency, and number of swings per minute.

Pendulum Parameters

Pendulum Length

Gravitational Acceleration (m/s²)

Presets:

Formula: T = 2π√(L / g) | f = 1 / T

Results

Enter values and click Calculate.

Summary

Enter pendulum length and gravity to instantly calculate period, frequency, and number of swings per minute.

How it works

Enter the pendulum length in meters (or select a preset unit).
Choose a gravitational acceleration — Earth standard (9.80665 m/s²) is pre-filled, or type a custom value for another planet.
The period T = 2π√(L/g), frequency f = 1/T, and swings per minute are computed instantly.
Use the "Solve for Length" toggle to work backwards: enter a desired period and get the required length.
Copy any result with one click.

Use cases

Physics homework and lab reports requiring pendulum period calculations.
Clock and metronome design where a precise beat frequency is needed.
Comparing pendulum behavior on different planets or moons.
Demonstrating the independence of period from mass to students.
Estimating the length of a grandfather clock pendulum from its tick rate.
Engineering applications involving oscillatory systems.

Frequently Asked Questions

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Last updated: 2026-05-23 · Reviewed by Nham Vu