Peak to RMS
Compute crest factor and dynamics from peak and RMS levels.
About Peak to RMS
The crest factor subtracts the average RMS level from the peak level, describing how much dynamic swing a signal has. Crest factor reveals how much headroom a mix really needs and whether compression has squashed the life out of it.
Formula
Peak to RMS
Crest factor = peak - RMS (in dB)
- dBFS
- Decibels relative to full scale
Worked example
With the default values below, Peak to RMS returns Crest Factor of 6.0. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Peak levelaccepts -60–0 dBFS
- -3 dBFS
- RMS levelaccepts -60–0 dBFS
- -9 dBFS
Results
- Crest Factor
- 6.0 dB
- Peak to RMS Ratio
- 2.00
- Dynamics
- Balanced dynamics
Step by step
- 1Values used
- 2Peak to RMS
- 3Crest Factor= 6.0 dB
- 4Peak to RMS Ratio= 2.00
- 5Dynamics= Balanced dynamics
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 2 decimal places, 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 Peak to RMS calculated?
Crest factor = peak - RMS (in dB) The crest factor subtracts the average RMS level from the peak level, describing how much dynamic swing a signal has.
Why does Peak to RMS matter?
Crest factor reveals how much headroom a mix really needs and whether compression has squashed the life out of it.
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.