LUFS to dBFS: normalising to −14, −16 or −23
Loudness normalisation is a gain calculation with a constraint attached. The gain is trivial — it is the difference between where you are and where you need to be. The constraint is that adding it may push a peak over full scale, and the only number that tells you so is the true peak.
Loudness normalisation calculator
Enter the loudness your track measured at, and its highest true peak. The tool reports the gain and whether the peak survives it.
The gain is the easy part
If a track measures −18 LUFS and the target is −14 LUFS, it needs 4 dB of gain. Both numbers are on the same scale, so the arithmetic is subtraction:
gain (dB) = target LUFS − measured LUFS
That is the whole calculation, and it is exact. The difficulty is entirely in what happens to the peaks afterwards, because adding 4 dB of gain moves the loudest peak by 4 dB too. A master peaking at −1 dBTP arrives at +3 dBTP, which is 3 dB past full scale, and no streaming platform will play that.
Why −14 LUFS is not −14 dBFS
This is the confusion that makes the first normalisation attempt go wrong. The two numbers share a minus sign and nothing else.
| dBFS | LUFS | |
|---|---|---|
| Measures | Digital peak level | Perceived loudness |
| Frequency weighting | None — flat | K-weighting, BS.1770 |
| Gating | None | Absolute at −70, then relative |
| Reference | 0 dBFS is the converter ceiling | −0.691 offset in the standard |
| Typical value at −14 | Peaks around −6 dBFS | −14 by definition |
A track at −14 LUFS usually peaks somewhere near −6 dBFS, not −14 dBFS. If you were expecting the peaks to land at −14 dBFS you would conclude the master was quiet when it is in fact leaving six decibels of headroom unused. That headroom is what lets a platform turn it up without clipping, and it is the reason loudness targets sit well below the ceiling.
True peak, not sample peak
The check has to be on true peak, and the distinction is not academic. A sample peak is the highest value at a sample instant. A true peak accounts for where the waveform reaches between those instants, after the DAC's reconstruction filter has run.
A heavily limited master is full of peaks that land between samples. Its sample peak can read −0.1 dBFS while the reconstructed output reaches +2 dBFS. Delivering that file produces audible clipping in the listener's DAC, and it is why an intersample peak detector exists at all. The tool above takes a true peak figure for exactly this reason.
What the targets are
| Target | Where it comes from | Notes |
|---|---|---|
| −14 LUFS | Streaming consensus | The default for most material across Spotify, Apple Music, YouTube and Tidal |
| −14.5 LUFS | Some platform documentation | Marginally conservative; useful if several versions exist |
| −16 LUFS | Genre convention | Dense, heavily compressed masters that would fight a −14 target |
| −18 LUFS | Genre convention | Classical, jazz and acoustic, where transients carry the music |
| −23 LUFS | EBU R128 | Broadcast; roughly −23 LUFS, the historical reference for delivery |
| −16.5 LUFS | Spoken word | Practical for podcasts, where a higher level invites listening fatigue |
Notice that the platforms do not vary the number by genre. Spotify normalises on the integrated value whatever the material is, which is precisely why genre convention exists on the mastering side: delivering dense electronic and sparse string music at the same integrated value leaves them at noticeably different perceived volumes.
When the gain will not fit
If the required gain pushes the true peak over the ceiling, there are three options, in the order worth trying.
- Lower the target. Moving from −14 to −16 removes 2 dB of pressure and may leave the master alone. A dense master normalised to −16 often sounds better than the same master squashed to hit −14.
- Use a limiter with a ceiling, not a brick wall. A transparent limiter holding −1 dBTP will catch only the handful of overshoots and leave the body of the master alone. This is the normal answer.
- Go back to the mix. A master peaking at −1 dBTP after limiting has very little dynamic range left. That is a mix decision, and it is not reversible downstream.
The tool's last two rows work out what ceiling a limiter would need and how much reduction that implies, which is a quick way to see whether option two is plausible or whether the reduction would be obvious.
Five mistakes worth avoiding
- Treating −14 LUFS as −14 dBFS. They are different quantities and the peaks will land far above the loudness figure.
- Checking sample peak after a limiter. The overshoot that matters happens between samples, after the reconstruction filter.
- Normalising a mix that is not finished. The integrated value moves as the track changes, so the gain you measured is only valid for the version you measured.
- Matching loudness across a catalogue and losing the dynamics. A quiet acoustic track raised to −14 will be pushed down hard, and a dense one raised to −14 will sound squashed. Matching dynamics matters more than matching numbers.
- Forgetting that LUFS is gated. Silence and very quiet passages are excluded, which is correct for programme material and wrong for a test tone or a single sustained note.
Formulas worth keeping
| Quantity | Expression |
|---|---|
| Gain to target | target LUFS − measured LUFS |
| Peak after gain | true peak dBTP + gain |
| Headroom | ceiling − peak after gain |
| Linear amplitude | 10gain/20 |
| Integrated loudness | −0.691 + 10 · log10 (gated mean square) |
| Absolute gate | −70 LUFS |
| Relative gate | 10 LU below the ungated integrated |
Summary
Gain is the difference between measured and target, and it is exact. What decides whether the master survives it is the true peak, measured after reconstruction rather than at sample instants. Target −14 LUFS for most material, lower for classical and dense masters, and check the peak rather than assuming the platform will take care of it.