Measure how loud audio really is
Streaming platforms normalize to LUFS — measure integrated, momentary, and short-term loudness plus peak.
Tools used in this guide
The job
Peak meters lie about loudness — a quiet-sounding master can hit 0 dBFS. LUFS (BS.1770) weights frequencies like human hearing and gates silence, giving a number platforms actually normalize to (−14 on YouTube/Spotify).
Drop the file
The analyzer resamples to 48 kHz, applies K-weighting filters, then computes integrated loudness with the standard −70 LUFS absolute gate and −10 LU relative gate, plus momentary/short-term maxima, LRA, and sample peak.
Worked example
A −20 dBFS sine reads about −23 LUFS — the K-weighting itself costs ~3 LU on pure tones. A real podcast measuring −16 LUFS will be turned down ~2 dB by a −14 LUFS platform.
Where it stops
Approximate BS.1770 — within ~0.3 LU of reference meters on typical program, not a certified measurement. True-peak isn't measured (sample peak only); mastering-critical work still wants a real meter.