What Is dBFS?
dBFS (Decibels relative to full scale): Decibels relative to full scale — the level of a digital audio signal, where 0 dBFS is the loudest possible and quieter sounds are negative.
Definition
dBFS stands for decibels relative to full scale. It measures how loud a digital audio signal is compared with the maximum the system can represent. 0 dBFS is that maximum, so every normal level is a negative number: -12 dBFS is louder than -30 dBFS.
Good Levels for a Microphone
| Level while speaking | Meaning |
|---|---|
| Below -45 dBFS | Too quiet — others will struggle to hear |
| -30 to -12 dBFS | Good speech level |
| -12 to -3 dBFS | Loud; fine for singing or loud voices |
| 0 dBFS | Clipping — the signal is cut off and distorted |
RMS vs Peak
- RMS level reflects average loudness — how loud speech sounds overall.
- Peak level is the loudest instant. Keep peaks below about -3 dBFS to avoid clipping.
dBFS is a digital measure and isn’t the same as the sound pressure level (dB SPL) of the room. The microphone test shows both RMS and peak levels in dBFS.
Measure It
Related Guides
Part of the TapTest glossary · More in audio & video tests.