A practical mastering tool that answers two questions at once: how much will a streaming platform turn my master up or down, and will that change push my true peaks past the ceiling? Enter your measured integrated LUFS and true peak, pick a target, and the calculator shows the normalization gain and the resulting peak budget.
How it works
Loudness normalization is just a single gain change applied to the whole track:
Gain change (dB) = Target LUFS − Measured LUFS
Post-normalization true peak (dBTP) = Measured true peak + Gain change
If your master is louder than the target, the gain change is negative (turned down), and your peaks drop with it — clipping is never a risk in that direction. If your master is quieter than the target, the gain change is positive (turned up), and your true peaks rise. If those raised peaks exceed your chosen ceiling (commonly -1.0 dBTP), the platform either can’t fully normalize you or you risk inter-sample clipping after lossy encoding.
The tool also reports your current peak headroom (the gap between your true peak and 0 dBTP) and the recommended limiter ceiling so the post-normalization peak lands exactly on your safety target.
Worked example
Your master measures -9 LUFS integrated with a true peak of -0.3 dBTP. Targeting Spotify’s -14 LUFS:
- Gain change = -14 − (-9) = -5 dB (Spotify turns you down 5 dB)
- Post-normalization true peak = -0.3 + (-5) = -5.3 dBTP — comfortably safe
Now flip it: a quiet master at -18 LUFS with a true peak of -0.5 dBTP targeting -14 LUFS:
- Gain change = -14 − (-18) = +4 dB (turned up 4 dB)
- Post-normalization true peak = -0.5 + 4 = +3.5 dBTP — over the ceiling, so the codec may clip. To stay under -1.0 dBTP after a +4 dB lift, the master’s true peak should have been at or below -5.0 dBTP.
Tips
- Master to a true-peak ceiling, not a sample-peak ceiling. Sample peaks can hide inter-sample overshoots that true-peak metering catches.
- A ceiling of -1.0 dBTP suits most platforms; use -2.0 dBTP when lossy codecs and aggressive normalization combine.
- Loudness is perceptual — pair this with the equal-loudness contour tool to understand why a -14 LUFS pop master and a -14 LUFS classical master feel very different.
Every calculation runs locally in your browser; nothing is uploaded.