Aliasing Frequency Calculator
Enter the known values and run the calculation.
Overview
Show where out-of-band content folds into sampled spectra and corrupts measurement results.
This tool shows where an out-of-band tone folds back into the sampled spectrum of a real acquisition system.
It is useful during DAQ planning, anti-alias filter checks, and post-test troubleshooting when a spectral line looks real but should not be.
The math and how it's used
Aliased frequency is found by folding the input tone back into the first Nyquist band.
The calculator also reports Nyquist frequency and Nyquist zone so you can see whether the tone is already inside the baseband or arriving from a higher zone.
Use this when you want a fast answer to where an out-of-band tone folds after sampling.
The math is straightforward, but whether the aliased tone actually shows up depends on the front-end bandwidth and how much anti-alias filtering is in front of the converter.
What to watch
Aliasing is not fixed by more FFT points. It is fixed by adequate sample rate, adequate front-end filtering, or both.
If the tone is near a band edge, front-end analog behavior can matter just as much as the digital sample rate you set in software.