Loudness Normalisation Gain Calculator (LUFS)

Understanding the LUFS loudness normalisation calculator — concept and principle

Streaming services and broadcasters measure how loud a programme sounds over its whole length and then adjust playback so that tracks and shows arrive at a similar loudness. This calculator tells you how much gain a platform target implies for your master, in decibels, and where your true peak will land after that change.

The same −5 dB moves both the loudness and the peak.

How it is calculated

Gain change (dB) = target loudness − measured integrated loudness.
Peak after gain (dBTP) = measured true peak + gain change.

Integrated loudness is in LUFS (loudness units relative to full scale; LKFS is the same unit under a different name). 1 LU equals 1 dB of level change. The targets offered are −14 (common streaming reference), −16 (Apple Music), −23 (EBU R128) and −24 (ATSC A/85).

The principle

Integrated loudness is measured with the method of ITU-R BS.1770: the audio is passed through a "K-weighting" filter that approximates the ear's sensitivity, its mean-square energy is averaged over time, and quiet passages are gated out so that silence does not drag the figure down. Because the result is on a decibel scale, normalisation is a single, constant gain: subtract the measured value from the target. The peak therefore shifts by the same amount.

Worked example

Inputs: measured −9 LUFS, target −14 LUFS, true peak −0.5 dBTP.
Gain: −14 − (−9) = −5 dB, so the platform turns the track down by 5 dB.
Peak after gain: −0.5 + (−5) = −5.5 dBTP.

Each point is the calculator re-run with only “Measured integrated loudness (LUFS)” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Measured integrated loudness (LUFS)	Gain change (dB)
-2.25	-11.75
-4.5	-9.5
-6.75	-7.25
-9	-5
-11.2	-2.75
-13.5	-0.5
-18	4

How to read the result

A negative gain means your master is louder than the target and will be turned down; the extra loudness bought with heavy limiting is lost, while the reduced dynamics remain. A positive gain means the track is quieter than the target; depending on the service and the listener's settings it may be raised, left as is, or raised with a limiter. If peak after gain would exceed 0 dBTP, raising it would clip without limiting. Broadcast delivery specifications also set a true-peak ceiling; EBU R128 uses −1 dBTP.

Common mistakes

Using short-term or momentary loudness instead of integrated loudness for the whole programme.
Reading sample peaks instead of true peak; inter-sample peaks can be higher after conversion or lossy encoding.
Assuming every platform's target and policy is fixed; services revise them, so check current documentation.

Keep in mind: Targets and normalisation behaviour differ between services and can change. This calculator applies a simple gain offset; it does not model limiters, user volume settings or album-mode normalisation.

Frequently asked questions

Should I master to −14 LUFS?

Not necessarily. Many engineers master for the sound they want and let normalisation adjust level; −14 is a reference, not a requirement.

What is the difference between LUFS and dBFS?

dBFS describes signal level relative to digital full scale, while LUFS describes perceived loudness measured with K-weighting and gating.

Sources: ITU-R BS.1770, Algorithms to measure audio programme loudness and true-peak audio level · EBU R 128, Loudness normalisation and permitted maximum level of audio signals · ATSC A/85, Techniques for Establishing and Maintaining Audio Loudness for Digital Television

Checked 8 Nov 2026. Standard textbook formulas in SI units, computed in your browser. For learning and estimates — real designs must follow your local codes and be checked by a qualified engineer.

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