Updated October 2026 · Loudness and levels
Peak shows the highest single moment, RMS shows the average level over a short window, and LUFS gives a loudness figure that tracks how loud the audio sounds to people. For speech, use LUFS for the overall level and peak to check for clipping.
Three numbers appear on almost every audio meter, and they are easy to mix up. Each one answers a different question. Knowing which question you are asking stops you chasing the wrong number, such as turning a voice up because the peak looks low when the loudness is already fine.
Peak meters show the highest single sample or moment in the file. They tell you how close you are to clipping, which is the point where the sound distorts. A peak that touches the top of the meter is a warning. Peak is useful for safety, but it does not tell you how loud the file sounds. A single loud consonant can set the peak while the rest of the voice is quiet.
RMS measures the average level over a short window, roughly the energy of the sound over time. It is closer to how loud a sound feels than peak is, but it does not account for how people hear different frequencies. Many older meters and some tools use RMS, which is why readings from different software can disagree.
LUFS, short for loudness units relative to full scale, is a measure based on how the ear responds to different frequencies. It gives a single figure for a whole file, called integrated loudness, and it can also show the loudness over short windows. Platforms and broadcasters use it to match the level of different programmes, which makes it the most useful number for speech and music.
The LUFS meter shows the loudness of a file in the units most platforms use. Use it at the end of a project, after cleaning and levelling, rather than at the start. The loudness guide explains which target suits which platform.
No single number describes everything. Two files with the same LUFS can sound different if one is very dynamic and the other is squeezed. Listen as well as look. The meter tells you the level; your ears tell you whether the balance is right.
Integrated LUFS, true peak and streaming targets. Runs in your browser, nothing is uploaded.
For the overall level of a finished file, LUFS. For clipping, the true peak. For a quick check while recording, the peak.
They measure different things, or use different windows and weighting. Check which measure each one uses.
No. It is still useful as a simple average, but LUFS is the better guide to how loud speech sounds.
Keep the peaks below full scale with some room to spare, and use LUFS for the target loudness.
