To measure LUFS, run the finished bounce through a meter that follows ITU-R BS.1770 and read the integrated value, which is the whole-song average that streaming services use for normalisation. You can do it in a few seconds with the free Solar Heavy online LUFS meter: drop the file in and it reports integrated LUFS, loudness range and true peak, and shows what the major platforms will do to your level.
The number on its own is only half the job. Below is how to take a reliable reading, how to interpret each value, and how to act on it in the mix or the master.
What LUFS actually measures
LUFS (Loudness Units relative to Full Scale) is a perceived-loudness measurement. Unlike a peak meter, it applies K-weighting, a filter that reduces the influence of deep lows and lifts the upper mids where the ear is most sensitive. That is why a bass-heavy trap beat and a bright acoustic track can peak at the same level and still measure several LU apart.
If you want the full background, What Is LUFS? covers the standard itself. This post is about using the measurement.
The three time windows
- Integrated: the average of the entire file, with silence and very quiet passages gated out. This is the number Spotify, Apple Music and YouTube act on.
- Short-term: a 3-second window. Useful for checking whether your chorus is much louder than your verse.
- Momentary: a 400 ms window. Handy for spotting single hits or drops that jump out.
Loudness range and true peak
Loudness range (LRA) describes the spread between the quieter and louder parts of the song, in LU. A heavily limited pop record often sits under 6 LU, while an orchestral piece can go past 15.
True peak (dBTP) is the highest level once the signal is oversampled, so it catches peaks that land between samples. Those inter-sample peaks are what clip when a WAV gets encoded to AAC or MP3. More on that in Inter-Sample and True Peak Metering.
How to measure LUFS with the free meter
- Bounce the final master at the sample rate and bit depth you will deliver. Measure the exact file you plan to upload, not a live playback of your session, so plugin latency and bus routing can’t skew the reading.
- Open the LUFS meter and drop the file in. Decoding and analysis happen in your browser, so unreleased music never leaves your machine.
- Read integrated LUFS first. This is your headline figure.
- Check true peak. Aim for −1 dBTP or lower. Very loud masters often need −2 dBTP to stay clean after encoding.
- Look at LRA. If it is far lower than your reference tracks, your limiter or bus compression is probably flattening the arrangement.
- Read the platform preview. It shows how much each service will turn your track down (or leave it alone), which tells you whether extra loudness is buying you anything.
The meter follows ITU-R BS.1770-4 and EBU R128 (K-weighting, 400 ms blocks with 75% overlap, a −70 LUFS absolute gate and a −10 LU relative gate), and its integrated, LRA and true-peak readings match ffmpeg’s ebur128 filter to within 0.1 LU on test material.
What to do with the reading
If the master is much louder than about −9 LUFS
Most services normalise to roughly −14 LUFS (Apple Music to about −16), so a −7 LUFS master will simply be turned down. What it keeps is the damage: squashed transients and a flat LRA. Pull the limiter’s input gain back 2–3 dB and A/B against the louder version at matched loudness. If the quieter one punches harder once levels are matched, keep it.
If it is quieter than your genre references
Measure two or three commercial songs in the same style first. Then work upstream rather than piling on limiting:
- Tame the sharpest transients on the drum bus with a fast compressor or clipper so the limiter has less to catch.
- Check the low end. Sub energy below 40 Hz eats headroom without adding much perceived loudness. A gentle high-pass on the master or the bass bus often frees 1–2 dB.
- Make sure the midrange is dense enough. Loudness perception lives in roughly 1–5 kHz, so a thin mid-range will measure quiet no matter how hard you limit.
If true peak is over −1 dBTP
Switch your limiter to true-peak mode (most modern ones have it) or lower its ceiling. Re-measure after the change, because oversampled limiters can still overshoot slightly on dense material. How to Master Music to Get an Exact True Peak and LUFS Reading walks through the process step by step.
Tips from the mastering chair
- Measure the whole song, never a loop. Integrated loudness of the drop alone will read 2–4 LU hotter than the full track.
- Match loudness before judging. Your ears will always prefer the louder version. Use the meter to bring two versions to the same integrated value, then decide.
- Treat short-term LUFS as an arrangement tool. If your chorus is only 0.5 LU louder than the verse, the drop may not land. A 2–3 LU lift usually feels intentional.
- Keep a note of your reference values. Writing down integrated LUFS, LRA and true peak for a few favourite records in your genre gives you a realistic target zone instead of a single magic number.
- Don’t master to the meter. Pick the loudness that suits the song. A dynamic ballad at −13 LUFS can sound bigger on Spotify than a crushed one at −8.
Who this is for
- Artists releasing on their own who want to check a master before it goes to a distributor.
- Producers sending beats who want consistent levels across a beat pack.
- Mix engineers checking how a mix-bus limiter is behaving before the track goes to mastering.
- Anyone comparing masters, such as an old version against a revision.
If you’d rather hand the loudness decisions to someone else, Solar Heavy also offers single track audio mastering.
Frequently asked questions
There is no single correct number. Spotify, YouTube, Tidal and Amazon Music normalise to about −14 LUFS and Apple Music to about −16 LUFS, and many modern masters sit between −14 and −9 LUFS integrated. Choose what suits the song and keep true peak at −1 dBTP or lower.
No. RMS is an unweighted average of signal power, while LUFS applies K-weighting and gating to reflect how loud music sounds to people. Two tracks with the same RMS can measure several LU apart. LUFS vs RMS vs dBFS explains the difference.
Usually because it is showing short-term or momentary loudness, or it was reset partway through playback. Integrated loudness has to be measured over the whole file from start to finish.
No. The file is decoded and analysed in your browser and never leaves your device.
It depends on genre. Heavily limited pop and EDM often land under 6 LU. Acoustic, jazz and film music commonly sit higher. Compare against references in your style rather than chasing a fixed figure.