Frequency Calculator

What Is Frequency?

Frequency $f$ counts how many complete cycles occur per second, measured in hertz (Hz). It is the reciprocal of the period and appears in waves, rotation, AC circuits, and oscillating systems.

Three Ways to Calculate Frequency

$$ f = \frac{1}{T} \qquad f = \frac{\omega}{2\pi} \qquad f = \frac{v}{\lambda} $$

$T$ is the period in seconds, $\omega$ is angular frequency in rad/s, $v$ is wave speed, and $\lambda$ is wavelength. Example: a 0.5 s period gives $f = 1/0.5 = 2$ Hz.

How to Use This Calculator

Choose the formula that matches your known values. Enter period, angular frequency, or velocity and wavelength, then read frequency in Hz, kHz, MHz, or GHz.

Frequently Asked Questions

What is the relationship between frequency and period?

They are reciprocals: f equals 1 divided by T. A longer period means a lower frequency.

How do I convert angular frequency to frequency?

Divide omega by 2 pi. For example, 377 rad/s corresponds to 60 Hz.

When do I use f equals v over lambda?

Use this for traveling waves when you know propagation speed and wavelength, such as sound or electromagnetic waves.

Can frequency be negative?

Frequency is defined as a positive scalar. Direction of travel is handled separately by the wave vector.

What units should I use?

SI frequency is hertz. This calculator converts period, angular frequency, and wavelength inputs from common engineering units automatically.

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What Is Frequency?

Three Ways to Calculate Frequency

How to Use This Calculator

Frequently Asked Questions

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