Aliasing Frequency Calculator
Calculate the apparent (aliased) frequency when a signal above the Nyquist limit is sampled.
Hz
Hz
Aliased Frequency
14,100 Hz
Nyquist Frequency22,050 Hz
Is Signal Aliased?1
Aliased Frequency vs Sampling Rate
How Aliasing Works
When a signal exceeds the Nyquist frequency (half the sampling rate), it "folds" back into the representable range, appearing as a lower frequency.
Formula
The aliased frequency is found by folding the signal into the first Nyquist zone:
f_alias = f_signal - round(f_signal / f_sample) x f_sample
If this result is above Nyquist, subtract from the sampling rate.
Example
A 30 kHz tone sampled at 44.1 kHz aliases to 14.1 kHz (44.1 - 30 = 14.1 kHz).Example Calculation
A 30 kHz signal sampled at 44.1 kHz.
- 01Nyquist: 44,100 / 2 = 22,050 Hz
- 0230,000 > 22,050, so aliasing occurs
- 03Alias: |30,000 - 1 x 44,100| = 14,100 Hz
- 04The 30 kHz signal appears as 14,100 Hz
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