Crest Factor
Measure the crest factor and headroom of an audio signal.
About Crest Factor
Crest factor is the gap between the loudest peaks and the sustained average level of a piece of audio. Masters with low crest factor sound loud but squashed, so balancing it is the heart of loudness and clarity.
Formula
Crest Factor
Crest factor = peak level - RMS level
- RMS
- The average (root-mean-square) signal level
Worked example
With the default values below, Crest Factor returns Crest Factor of 12.0. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Peak levelaccepts -120–0 dBFS
- -3 dBFS
- RMS levelaccepts -120–0 dBFS
- -15 dBFS
Results
- Crest Factor
- 12.0 dB
- Headroom
- 12.0 dB
- RMS Gap
- 12.0 dB
Step by step
- 1Values used
- 2Crest Factor
- 3Crest Factor= 12.0 dB
- 4Headroom= 12.0 dB
- 5RMS Gap= 12.0 dB
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Crest Factor calculated?
Crest factor = peak level - RMS level Crest factor is the gap between the loudest peaks and the sustained average level of a piece of audio.
Why does Crest Factor matter?
Masters with low crest factor sound loud but squashed, so balancing it is the heart of loudness and clarity.
What values do I need to enter?
This calculator takes 2 inputs: Peak level, RMS level. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.