Pick a genre and platform — get the target LUFS, True Peak and chain settings.
The target depends on where the track will be heard. For streaming, aim for −14 LUFS so Spotify, YouTube and TikTok will not turn it down. Apple Music is stricter at −16 LUFS. Club playback and vinyl releases follow different rules.
Genre adjusts that number. Dense electronic music is traditionally mastered louder and handles it better — there is less dynamic range to begin with. Jazz, classical and acoustic need headroom: compression destroys what matters most in them.
Loudness is not the only parameter. True peak must stay at or below −1 dBTP, or the codec will clip when encoding to AAC or Opus and your listener will hear crackle on their phone that is not in your file.
The second figure is loudness range, LRA. A value around 3 LU means the track is squashed nearly flat. Acceptable for dance music, fatal for a ballad: breaths, quiet verses and the lift into the chorus all disappear.
Set the number as your mastering target and check whether it is reachable without clipping. If the limiter hits the ceiling and still falls short, the track is already compressed as far as it goes: raise the level in the mix rather than pushing the limiter harder.
To see how platforms will treat your finished master, use the loudness penalty page.