Mastering calculator: how loud should my song be?
Enter your track's integrated loudness and true peak, pick where it will play. You get the gain change, the peak after it, whether you need a limiter — and what Spotify, Apple Music or YouTube will do with the file. Runs in your browser; nothing is uploaded.
How to read the result
Gain change is the difference between the target and your integrated loudness. Positive means the track has to get louder to reach the target, negative means quieter.
Peak after gain is your true peak moved by the same amount. If it lands above the ceiling, a true-peak limiter has to take the difference off the peaks. That difference is the limiting the calculator reports; if the peak lands below the ceiling, you have headroom instead.
What the platform does applies if you upload the track as it is. Streaming services normalise playback: louder tracks are turned down to the reference level, so pushing a master past it buys nothing and costs dynamics.
What LUFS and true peak are
LUFS (loudness units relative to full scale) measures perceived loudness over the whole track, weighted the way the ear hears frequencies, as defined in ITU-R BS.1770. A track at −9 LUFS sounds about 5 dB louder than one at −14 LUFS. Streaming services use integrated LUFS to decide how much to turn a track down.
True peak (dBTP) is the highest level of the waveform including the points between samples, found by oversampling. A master can show −0.1 dB on a sample-peak meter and still have true peaks above 0, which clip after MP3 or AAC encoding. More in true peak explained.
Platform loudness targets
| Where | Plays at | Louder tracks | Quieter tracks |
|---|---|---|---|
| Spotify | −14 LUFS | turned down | turned up only as far as peak stays below −1 dBTP |
| Apple Music | −16 LUFS | turned down (Sound Check) | may be turned up, within peak headroom |
| YouTube | −14 LUFS | turned down | not turned up |
| Amazon Music | about −14 LUFS | turned down | usually play quieter |
| Tidal | −14 LUFS | turned down | not turned up |
| SoundCloud | no normalisation | play louder | play quieter |
| Podcasts (Apple spec) | −16 LUFS | most apps play the file as it is | |
| Club / DJ | about −9 to −6 LUFS | no normalisation; the DJ sets gain by ear | |
Targets and behaviour change; the listener's settings (Spotify Loud or Quiet, normalisation switched off) change them too. Per-service detail: streaming loudness targets and Spotify loudness.
Using it with Suno and Udio tracks
Downloads from AI music generators are often already loud, around −10 to −8 LUFS, with true peaks above 0 dBTP. Put those numbers in: for Spotify the calculator will show the track turned down by several dB, and a true peak that needs fixing before release. If the track is quiet and uneven instead, it shows how much gain and limiting it takes to get there. Both are what mastering a Suno track is about.
How loud should my song be for Spotify?
Spotify plays music at about −14 LUFS integrated. A louder master is turned down to that level, so there is no gain in going much louder. Keep true peak below −1 dBTP, or below −2 dBTP if the master is louder than −14 LUFS.
Should I master exactly to −14 LUFS?
No, −14 LUFS is where the platform plays your track, not a rule for the master. Many good masters sit between −14 and −9 LUFS. What matters is that the track still sounds open after the platform turns it down, and that true peak stays under the ceiling.
What happens if my track is quieter than the target?
YouTube and Tidal never turn tracks up, so a quiet master plays quieter. Spotify turns quiet tracks up only as far as the true peak stays below −1 dBTP. SoundCloud does not normalise at all.
Why does the calculator say I need a limiter?
Raising a track by the needed gain also raises its peaks. If the peaks would go above the ceiling, a true-peak limiter has to hold them down. A few dB of limiting is normal; more than about 6 dB usually squashes transients.
Do Suno and Udio tracks need mastering?
Often yes. AI-generated tracks are usually either quite loud with true peaks above 0 dBTP, or uneven in level. Measuring loudness and true peak first tells you how much work the master needs.
Is the calculator accurate?
The gain arithmetic is exact. How a platform plays your track depends on the listener's settings, and the peak after limiting depends on the limiter. Use the result as a plan, then measure the finished file.