Wondering what is true peak? It is the actual peak level your audio reaches between the digital samples, which can be higher than the peaks your normal meter shows. True peak matters because those hidden inter-sample peaks can cause clipping and distortion when your file is converted to analogue or to a lossy format like MP3 or AAC.
Quick answer
- Sample peak measures the level at each sample point.
- True peak estimates the real waveform peak between samples (inter-sample peaks).
- True peaks can exceed 0 dBFS even when sample peaks do not.
- Set your limiter ceiling to around -1 dBTP to stay safe.
What is true peak versus sample peak?
A standard peak meter reads the level at each individual sample. But the continuous analogue waveform that gets reconstructed from those samples can rise above the highest sample value in the gaps between them. These are called inter-sample peaks. True peak metering reconstructs (oversamples) the waveform to estimate those between-sample maximums, giving you the real ceiling the signal will hit. This is closely related to how digital audio is sampled — see sample rate and bit depth explained.
Why true peak matters
- Digital-to-analogue conversion: your DAC reconstructs the waveform, so inter-sample peaks can clip the converter even if no sample hit 0 dBFS.
- Lossy encoding: MP3 and AAC encoding can push levels slightly higher, turning a borderline file into a clipping one — one reason the choice between WAV and MP3 affects how much margin you need.
- Streaming standards: platforms recommend a true peak ceiling (commonly -1 dBTP) and may flag or penalise files that exceed it.
In short, a master that looks safe on a sample meter can still distort on real playback. True peak metering catches that.
What does dBTP mean?
True peak is measured in dBTP (decibels true peak), referenced to full scale just like dBFS. A reading of -1 dBTP means the true (inter-sample) peak sits one decibel below the digital ceiling. Keeping a margin here is what prevents conversion and encoding clipping.
How inter-sample peaks actually happen
It helps to picture what a converter does on playback. Your audio file stores a series of discrete sample values, but those samples are only snapshots of a smooth analogue waveform taken thousands of times per second. To play the file back, the converter has to draw a continuous curve back through those points. Because the curve is smooth rather than a series of steps, it can bow upward between two high samples and momentarily rise above either of them.
This is most likely to bite you in a few common situations. Bass-heavy and heavily limited material is the worst offender, because squashing the dynamic range pushes lots of samples right up near the ceiling, leaving plenty of room for the curve to overshoot between them. Sharp transients — think snare hits, plucked strings or percussive synths — also create steep slopes that the reconstructed waveform can exceed. The hotter and denser your master, the more inter-sample peaks you tend to generate.
How to control true peak
Use a true peak limiter (often labelled “true peak” or “ISP” mode) as the last gain stage in your master. Set the ceiling to around -1 dBTP for streaming-bound material, or even -1.5 dBTP if the track encodes hot. Then check the result on a true-peak-capable meter such as Youlean Loudness Meter, which displays true peak alongside LUFS. Most mastering limiters (including those in the best free mastering plugins) include a true peak option in their settings.
True peak goes hand in hand with loudness targets, so read it together with how loud your master should be and our overview of what mastering does. For more, browse the mixing and mastering hub.
A simple workflow for clean peaks
- Mix with headroom. Leave your mix bus peaking comfortably below 0 dBFS so the mastering chain has room to work without forcing the limiter to clamp down hard — this is exactly why headroom is worth protecting.
- Limit, then measure. Place the true peak limiter last, enable its true peak or ISP mode, and set the ceiling to -1 dBTP. Do not rely on a plain sample-peak readout at this stage.
- Render and re-check. Bounce the final file and run it back through a true-peak meter, ideally on the exact format you will deliver. The render itself can shift levels slightly, and if you are reducing bit depth you should apply dithering on the final export.
- Account for the codec. If you know the track is going to lossy streaming, drop the ceiling to -1.5 dBTP. The slight loss in measured loudness is inaudible and well worth the safety margin.
Common mistakes
- Trusting the sample meter alone. A file can read 0.0 dBFS on a sample meter and still overshoot on playback. Only true peak metering reveals it.
- Setting the ceiling to 0 dBTP. Even at exactly 0 dBTP you leave no margin for codec gain. Always keep at least 1 dB of headroom.
- Chasing maximum loudness. The harder you push the limiter, the more inter-sample peaks you create. Streaming platforms normalise loudness anyway, so an over-squashed master often sounds worse without being any louder to the listener.
- Forgetting to enable true peak mode. Many limiters default to ordinary sample-peak limiting, so the true peak or ISP option has to be switched on deliberately.
Frequently asked questions
What true peak level should I master to?
For streaming, aim for a true peak ceiling around -1 dBTP. If your track is loud and likely to clip during MP3 or AAC encoding, -1.5 dBTP gives extra safety with no audible downside.
Why is my true peak higher than my sample peak?
Because the analogue waveform reconstructed from your samples can rise above the highest sample value in the gaps between samples. True peak metering oversamples to reveal these inter-sample peaks, which a standard sample meter misses.
Do I need a special meter to read true peak?
You need a meter or limiter with true peak (ISP) measurement. Many limiters have a true peak mode, and free tools like Youlean Loudness Meter display true peak in dBTP alongside loudness.
Does true peak matter if I only release on CD or WAV?
It still matters, just less critically. Lossless formats do not add the encoding gain that pushes MP3 and AAC files over the edge, but the digital-to-analogue converter still reconstructs the waveform on playback, so inter-sample peaks can clip the listener’s DAC. Keeping a small margin below the ceiling is good practice for any delivery format.
