Guides

LUFS, true peak and crest factor, explained for people who just want the song to sound right

Updated 2026-09-06

A mastering report is three numbers and a lot of decoration. Here are the three, in plain terms.

LUFS: how loud it feels

Loudness Units relative to Full Scale. It measures perceived loudness over the whole track, weighted the way ears hear, so a bassy song and a bright song with the same LUFS feel equally loud. Integrated LUFS is the average across the song. Short-term LUFS is a three second window, which is what you see moving on a meter. Streaming services normalize on integrated. A pop master lives around -10. A quiet folk record around -14. Spotify plays both back at -14.

True peak: will it distort

The highest point the waveform reaches between samples, measured with oversampling. A normal peak meter misses the in-between points, which is where clipping happens after a codec rebuilds the waveform. -1 dBTP is the safe ceiling for streaming. Above that, expect crackle on the loud parts after upload.

Crest factor: how much punch is left

The distance between the peaks and the average level, in dB. A drum hit is a peak. The sustained chord under it is the average. A high crest factor, 14 dB or more, means the transients still jump out. Push loudness too far and crest drops under 8 dB, and the song turns into a flat wall. Good masters are loud and still have crest. That is the whole craft.

Reading them together

• -10 LUFS, -1.0 dBTP, crest 11 dB: a competitive pop master.
• -7 LUFS, -0.3 dBTP, crest 6 dB: loud, clipping after upload, no punch left.
• -17 LUFS, -3 dBTP, crest 16 dB: a mix, not a master. Platforms will make it sound small.

Burnish prints all three, before and after, on every report. The free analysis gives you the before.