What is the Nyquist rate?

The Nyquist rate is the minimum sampling frequency required to represent a signal without aliasing. It equals exactly twice the highest frequency component in the signal: f_s,min = 2 × f_max.

What is the sampling period?

The sampling period T is the time between consecutive samples. It is the reciprocal of the sampling rate: T = 1 / f_s. For a 44.1 kHz audio system, T ≈ 22.68 microseconds.

Aliasing occurs when a signal is sampled at a rate below the Nyquist minimum. High-frequency components fold back into the baseband and appear as false lower-frequency signals, corrupting the digital output.

Why do real systems oversample beyond the Nyquist minimum?

Ideal brick-wall anti-aliasing filters are not physically realizable. Practical filters have a gradual roll-off, so engineers add oversampling margin (typically 1.5× to 10× the Nyquist rate) to allow the filter to attenuate out-of-band frequencies before they alias.

What is the maximum frequency a sampling rate can represent?

A system sampling at f_s can accurately represent signals up to f_s / 2, known as the Nyquist frequency. Frequencies above this limit alias to lower frequencies in the digital output.

Sampling Rate Calculator

Enter a sampling rate or signal frequency to get the Nyquist rate, sampling period, and aliasing thresholds for DSP design.

Sampling Parameters

Sampling Rate (f_s) (optional)

Max Signal Frequency (f_max) (optional)

Quick Presets

Enter at least one value and press Calculate

Summary

The Sampling Rate Calculator helps engineers and students determine the correct sampling parameters for digital signal processing (DSP) systems. Enter either a known sampling rate to find the sampling period and maximum representable frequency, or enter a signal frequency to compute the minimum required sampling rate (Nyquist rate). An optional aliasing check compares your actual sampling rate against the Nyquist criterion and reports the oversampling margin.

How it works

Choose your input mode: enter a sampling rate or a signal frequency.
Type the frequency value and select the unit (Hz, kHz, MHz, or GHz).
The calculator applies the Nyquist-Shannon theorem: f_s,min = 2 × f_max.
Sampling period T is computed as T = 1 / f_s.
Maximum representable frequency is f_max = f_s / 2 (the Nyquist frequency).
Optionally enter both values to check whether aliasing will occur.

Use cases

Selecting an ADC sampling clock for audio, RF, or sensor applications.
Verifying that a data-acquisition system captures all relevant signal content.
Computing the sampling period for microcontroller timer configuration.
Checking whether a proposed sampling rate satisfies the Nyquist criterion.
DSP coursework: exploring the relationship between sample rate and bandwidth.
Oscilloscope setup: confirming sample rate is sufficient for the measured signal.
Medical devices: sizing ECG or EEG digitizer clocks for clinical bandwidth.
Communications: calculating IF sampling requirements for software-defined radio.

Frequently Asked Questions

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