LufsReady

Free tool

Gain to target calculator

Enter your file's integrated loudness and true peak, pick a target, and see the gain you need, where the peaks will land and whether a limiter has to step in.

From the LUFS meter or any BS.1770 meter.
Use the true peak, not the sample peak, if you have it.
Filled in from the target; change it if your delivery spec differs.
Gain to apply–dB
True peak after gain–dBTP
Peak limiting needed–dB

Enter your measurements to see the result.

How the calculation works

Integrated loudness and peak level both move one-for-one with gain: add 3 dB and a file measured at −19 LUFS with a −4 dBTP peak becomes −16 LUFS with a −1 dBTP peak. So the calculator does three subtractions:

  • Gain to apply = target loudness − current loudness.
  • True peak after gain = current true peak + gain.
  • Peak limiting needed = true peak after gain − ceiling, when that is above zero. That is how far a true-peak limiter set to the ceiling must pull down the highest peak.

For example, an episode at −22.4 LUFS with a true peak of −4.1 dBTP needs +6.4 dB to reach −16 LUFS. Its peaks would land at +2.3 dBTP, so a limiter set to −1 dBTP has to remove 3.3 dB from the loudest peak. Most of the audio passes through the limiter untouched; only the moments above the ceiling are reduced.

What the numbers do not tell you

Limiting takes a little energy out of the peaks, so after heavy limiting the integrated loudness can fall a few tenths of a dB short and is worth measuring again. If you will encode to MP3 or AAC afterwards, the encoder can raise peaks slightly, so re-measure the encoded file too, or set the limiter a little below the ceiling. Raising the level also raises the background noise by the same amount, which matters for ACX audiobooks and their −60 dB noise-floor limit.

Targets in the list come from the loudness targets reference. LufsReady applies the gain, a 4x-oversampled true-peak limiter and a final measurement for you with its delivery presets.

Frequently asked questions

Why do I need a limiter when my peaks are below 0 dBFS?
Gain moves everything by the same amount. If your file is 6 dB too quiet and its true peak is at −4 dBTP, raising it by 6 dB puts the peak at +2 dBTP, above any delivery ceiling. A true-peak limiter holds those few peaks down while the rest of the audio gets louder.
How much limiting is too much?
There is no fixed rule. A few dB of peak limiting on speech is usually hard to hear. When the calculator asks for much more than that, a compressor before the limiter usually sounds better than one limiter doing all the work.
Will the result land exactly on the target?
Very close, but not always exactly. Limiting removes a little energy from the peaks, so integrated loudness can end up a few tenths of a dB under the target when the limiter works hard. Measure the processed file again and add the small difference if needed.
Can I use this for ACX audiobooks?
The same arithmetic applies to RMS: gain = target RMS − current RMS, and the peaks and the noise floor move by the same amount. The ACX check runs that calculation for you, including where the noise floor will end up.

Master it to spec automatically

Upload a recording, pick Apple Podcasts, ACX, EBU R 128 or your own target, and download a file that meets it, with a before-and-after report. New accounts get 60 free minutes after confirming their email.

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More free tools

LUFS Loudness MeterIntegrated loudness, true peak and loudness range of any file, measured in your browser.ACX Audiobook CheckRMS, peak and noise floor against ACX submission requirements.Clipping DetectorFind clipped samples and over-the-ceiling peaks before you publish.Loudness Targets ReferencePodcast, audiobook, streaming and broadcast targets in one table.