Sample Rate (Nyquist)
Calculate minimum sample rate using Nyquist theorem. Enter circuit values to calculate the selected electrical quantity.
Signal Frequency
Electronics guide · Signals, timing, and radio frequency
About Sample Rate and Nyquist Calculator
Relate a sampling rate to the Nyquist frequency and estimate the minimum sampling rate for a selected signal frequency. This is a basic sampling-theory check; real analog-to-digital conversion also requires filter design and margin.
Signal and RF calculations connect frequency, period, wavelength, bandwidth, sampling, impedance, and ratios. Results often assume ideal propagation or a simplified signal model; real cables, antennas, clocks, and converters can add losses, tolerances, reflections, and environmental effects.
How to Use This Tool
- 1.Enter the sample rate or signal frequency in the mode shown by the calculator.
- 2.Choose the correct frequency unit and calculate the Nyquist value or required rate.
- 3.Check the result against the highest signal component and the analog anti-aliasing filter in your system.
Technical Details to Check
1.Frequency and time are linked
For a periodic signal, period is the reciprocal of frequency. Convert prefixes carefully: hertz, kilohertz, megahertz, and gigahertz differ by powers of one thousand.
2.Propagation depends on the medium
Wavelength is related to frequency and propagation speed. A free-space estimate differs from wavelength in a cable or material where the signal travels more slowly.
3.Logarithmic ratios need a reference
Decibels and related units describe ratios, often with a stated reference such as dBm. Check whether the tool is converting power, voltage, or a normalized ratio before using the value.
4.Sampling is not reconstruction quality
A sampling condition can help assess whether a signal's frequency content is representable, but real filters, clock jitter, noise, and system bandwidth also affect sampled data.
How the Calculation Works
The Nyquist frequency is half the sampling rate: fN = fs/2. For ideal reconstruction of a band-limited signal, the sampling rate must be greater than twice its highest frequency component. A practical system uses margin and an anti-alias filter because real filters are not brick walls.
Worked Example
A 48 kHz sample rate has a Nyquist frequency of 24 kHz. That does not mean every signal near 24 kHz is captured perfectly.
Where This Tool Can Help
Review a sampling-rate choice for audio, sensor data, or a basic signal-processing exercise.
Converting signal units
Move between frequency, time, wavelength, or power representations while keeping the source unit and reference clear.
Checking a communications setup
Estimate baud timing, clock tolerance, or signal ratios, then compare the result with the transceiver and protocol requirements.
Planning an RF or antenna estimate
Use a frequency-based result as a starting point and account separately for material, antenna geometry, matching, and the surrounding environment.
Reviewing sampled signals
Check a theoretical sampling relationship before testing the actual signal path, filters, converter limits, and clock quality.
Tips for More Reliable Results
- Write down the frequency, time, impedance, and reference units before entering a value.
- Check whether the formula assumes free-space propagation, ideal components, or a matched load.
- For dB values, identify the reference and whether the underlying quantity is power or amplitude.
- Compare theoretical results with datasheets, measured behavior, and the operating frequency range.
Limitations and Assumptions
The calculator does not model filter roll-off, jitter, quantization, bandwidth, or oversampling. Meeting the arithmetic threshold alone does not guarantee good measurement or reconstruction.
Signal calculations describe a model, not a complete measurement of a physical system. Propagation medium, component tolerance, noise, impedance mismatch, bandwidth, and instrument limitations may not be represented by the inputs.
Frequently Asked Questions
What is the Nyquist frequency at 96 kHz?
It is 48 kHz, half the sampling rate.
Is sampling exactly twice the signal frequency enough in practice?
Practical systems need filtering and margin; exact equality is not a robust design target.
Does Nyquist describe bit depth?
No. Bit depth affects amplitude resolution, while Nyquist concerns frequency sampling.
Is wavelength always the free-space value?
No. The medium changes propagation speed, so a cable or material can have a shorter wavelength than free space.
Does a sampling calculation guarantee a clean digital signal?
No. Filtering, noise, clock accuracy, converter performance, and signal bandwidth also matter.