Calculators
Pendulum Period Calculator
Solve for pendulum period, frequency, or length using consistent units locally in your browser.
Choose what to solve for, then enter the other two values using consistent units (for example, metres with metres per second squared for seconds). Use 9.81 for Earth gravity. This models a simple pendulum with a small swing and no air resistance. Calculations run locally in your browser; your values are not uploaded or stored.
Solve simple pendulum swing timing without uploading your values.
Enter the pendulum length with gravity to calculate period or frequency, or enter the period with gravity to calculate length, using consistent units, such as metres with metres per second squared for seconds. The calculator applies the small-angle pendulum formulas with your gravity value and shows the matching result locally without being uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
Which formulas does the pendulum period calculator use?
It uses period = 2π × √(length ÷ gravity), frequency = (1 ÷ 2π) × √(gravity ÷ length), and length = gravity × (period ÷ 2π)². For example, a length of 1 length unit with a gravity of 9.81 gives a period of about 2.006 time units and a frequency of about 0.498 oscillations per time unit.
Which units should I use?
Use the same length and gravity units on both inputs, such as metres with metres per second squared for seconds. Use 9.81 for Earth gravity. The answer is reported in the matching combined time, frequency, or length unit.
Which inputs are accepted?
Enter values greater than zero up to 1,000,000,000,000. Zero, negative, missing, or non-numeric entries show a clear error instead of a result.
Does this calculator account for wide swings or air resistance?
No. It models an ideal simple pendulum with a small swing angle, a massless string, a point mass, and no air resistance or friction, so real-world pendulum clocks with wide swings or drag will differ slightly.
Do my values stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.