How to Read Loudness Numbers: What They Show and What They Miss

October 17, 2026 · All posts

LUFS stands for Loudness Units relative to Full Scale, and it measures perceived loudness. A loudness meter that follows ITU-R BS.1770, the method behind EBU R128, shows several readings at once: integrated loudness for the whole track, short-term and momentary loudness for parts of it, loudness range (LRA) for how far the level moves, and true peak in dBTP for the highest point of the reconstructed waveform.

This guide shows how to read each number, which platform figures to compare it with, and what the numbers do not tell you. You can check your own file with the free LUFS checker while you read.

The readings and what each one shows

The LUFS checker gives you integrated loudness, momentary maximum, LRA and true peak for your own file, free and without sign-up.

Integrated loudness: the number platforms use

Integrated loudness is the average loudness of the whole track. The meter starts by applying K-weighting, a filter that roughly follows how the ear hears frequencies, and then averages the energy over time. Two gates keep out the quiet parts: an absolute gate at −70 LUFS, and a relative gate 10 LU below the level of the ungated track. Silence at the start or end of a file does not drag the number down.

Platforms use their own references. The table shows the figures on Echoteka's platform pages, checked between 19 September and 9 October 2026:

These are references that can change, so check the platform's own documentation before a release.

True peak: why −1 dBTP and not 0

A file can have no sample above 0 dBFS and still clip after conversion. The waveform between two samples can rise above both neighbours, and a playback device or encoder reconstructs that curve. Such a peak is called an inter-sample peak. A sample peak meter shows only the stored values. A true peak meter reconstructs the waveform, oversamples it (ITU-R BS.1770 calls for at least four times) and reports the highest point in dBTP. The true peak page explains the method in more detail.

Lossy streaming encoders add to the problem. AAC, MP3 and Ogg streams can create peaks above those in the original file, which is why the usual ceiling is −1 dBTP. Echoteka's Spotify figures give the same logic: below −1 dBTP in general, and below −2 dBTP for tracks louder than −14 LUFS.

LRA: how much room the track has left

LRA is the reading that tells you how much room a track has left. In Echoteka's measurements of 248 Suno exports, made before any processing, the median LRA was 5.8 LU, and 40% of exports sat below 5 LU. A low LRA is not a fault in itself. It means there is less range left to give up before the track sounds flat, and that matters more once a limiter is involved. The Suno loudness report has the full method.

Reading the meter while you work

Read the meter during playback, not only at the end. Loop the section you are adjusting, watch the short-term reading while you move the level, and check integrated loudness once the whole song has played through. The table lists common readings and what to do with them:

A three-step check on your own track

1. Measure the whole track, not one section. Integrated loudness is the number to compare with a target. LRA shows how much dynamics is left.
2. Read true peak. If it is above −1 dBTP, lower the limiter's ceiling and export again.
3. Find the loudest section. Momentary and short-term maxima show which part sets the level.

The gain a platform applies is roughly its target minus your integrated loudness. A track at −9 LUFS with a −14 target is turned down by about 5 dB. The mastering calculator shows that gain change for each target, the peak after the gain and whether a limiter is needed. It runs in the browser, and the file is not uploaded.

What the numbers do not tell you

A meter reports loudness, peaks and range. It does not tell you whether the tonal balance is right, whether the stereo image holds up on a phone speaker, or whether the song is good. Each reading also has a blind spot:

• Integrated loudness is one average. Two tracks with the same number can have very different peaks and dynamics.
• True peak gives the highest point of the waveform, not how a clip would sound. Check the sound as well.
• LRA shows the spread of levels, not whether the arrangement works.

Use the readings for the decisions they can support, which are level, peaks and dynamics, and listen for the rest.

Common mistakes

• Comparing integrated values of different parts. A chorus, a loop or an intro gives a different integrated number from the whole track. Compare full tracks with full tracks, measured the same way.
• Confusing peak with true peak. A sample peak at −0.5 dBFS does not mean the track is safe. Check the true peak in dBTP.
• Reading momentary max as the level of the song. Momentary is a 400 ms snapshot. It describes a moment, not the track.
• Mixing meters. RMS and LUFS are different scales: RMS does not use K-weighting or gating. Use the same meter for every file you compare.
• Chasing −14. −14 LUFS is a playback reference, not a quality score. A track at −14 with no dynamics can sound worse than one at −12 with room to move.
• Assuming louder wins. Platforms turn loud tracks down, so a higher LUFS number does not make a track louder on the platform.

How to do it in Echoteka

• The LUFS checker shows integrated LUFS, true peak, momentary maximum, LRA, sample peak, crest factor and stereo correlation. It checks against Spotify and YouTube at −14 LUFS, and against Apple and podcasts at −16 LUFS.
• The checker is free and needs no sign-up. It accepts files up to 50 MB, allows 20 checks an hour per IP address, and does not keep the file.
• The mastering calculator shows the gain change for a platform target and the peak after that gain.
• Every Echoteka master comes with a before-and-after report on LUFS, true peak, LRA, crest factor and stereo. If a target was not reached, the report says so.

FAQ

What is LUFS? A measure of perceived loudness for a whole programme. It weights frequencies the way the ear hears them and averages loudness over time with gating. Streaming platforms use it as a reference.

What LUFS should a track be for Spotify? About −14 LUFS integrated, with true peak below −1 dBTP, and below −2 dBTP for tracks louder than −14 LUFS.

Is LUFS the same as RMS? No. RMS is a plain average of level. LUFS applies K-weighting and gating, so it follows loudness as the ear hears it.

What does LRA mean? Loudness range, in LU. It is the spread between quieter and louder sections, measured as the difference between the 10th and 95th percentiles of short-term loudness.

Does the LUFS checker keep my file? No. The file is not stored after the check.