EBU R 128 asks for programme loudness normalised to -23.0 LUFS. The plus or minus 1.0 LU window that most people quote is, in the current text, a tolerance for cases where hitting the target is not practical, such as live programmes, and quality control may allow only plus or minus 0.2 LU for measurement error. A file-based delivery should land on -23.0 LUFS, not anywhere between -24 and -22. WavSpec, a Windows app from Automata Labs, corrects a batch of audio files to the exact target of a named spec, re-measures every delivered file from disk, and writes a report that shows the result.
This guide reads the tolerance clauses in the current EBU R 128 (the November 2023 edition, version 5), explains how they changed since 2010, and shows what that means for a file you are about to deliver.
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What does EBU R 128 say about tolerance?
The recommendation is short, and the tolerance sits in three separate clauses. We read them in the EBU R 128 PDF on the EBU’s R 128 page today:
| Clause | What it says | Who it is for |
|---|---|---|
| h) Target | Programme Loudness “shall be normalised to a Target Level of -23.0 LUFS” | Everyone |
| h) Live tolerance | ”Where attaining the Target Level is not achievable practically (for example, live programmes), a tolerance of ±1.0 LU is permitted” | Live and similar cases |
| h) Warning | ”A broadcaster should ensure that a deviation from the Target Level towards the limits of the tolerance does not become standard practice” | Broadcasters |
| i) QC tolerance | ”a tolerance of ±0.2 LU is allowed in order to take account of measurement errors” | Quality control and loudness workflows |
| m) True peak | No more than -1 dBTP in production, with a measurement tolerance of ±0.3 dB | Everyone |
Read together, the rule for a finished, file-based programme is simple: aim at -23.0 LUFS. The 1 LU window exists for programmes that cannot be adjusted after the fact, and the EBU explicitly warns against treating its edges as normal. The 0.2 LU allowance exists because two compliant meters can disagree slightly, not as a creative margin.
Why do so many people say R 128 allows plus or minus 1 LU?
Partly history and partly convenience. The document’s own history table shows how the tolerance moved:
| Version | Date | Change recorded by the EBU |
|---|---|---|
| 1 | February 2010 | First published |
| 2 | August 2011 | Relative gate changed from -8 to -10 LU |
| 3 | June 2014 | Target level tolerance changed to ±0.5 LU (except live programmes) |
| 4 | August 2020 | Tolerances updated; references to R 128 s1 and s2 added |
| 5 | November 2023 | References to R 128 s3, s4 and Tech 3401 added |
So a delivery checklist written between 2014 and 2020 may say plus or minus 0.5 LU for non-live work. The current text frames plus or minus 1.0 LU as the practical limit for live programmes and adds the 0.2 LU measurement allowance. Version 5 did not change the numbers; it added pointers to the radio and cinema supplements.
The other reason is convenience. A window is easy to put on a meter, and many people turn “within tolerance” into “anything in the window is fine”. For a pre-recorded file there is no reason to deliver at -22.2 LUFS when gain can put it at -23.0.
Do broadcasters use the same numbers?
Not always. EBU R 128 is a recommendation; each broadcaster publishes its own delivery specification on top of it, and that document is the one your file is checked against. Two examples we have covered:
- The UK DPP AS-11 specification uses -23 LUFS with plus or minus 0.5 LU for pre-recorded programmes. Our DPP AS-11 delivery guide has the details.
- The 2025 ARD, ZDF and ORF production guidelines set their own tolerances and short-form rules, covered in our TPR 2025 loudness guide.
Short-form content (adverts, promos and trailers) follows R 128 s1, which adds a short-term loudness maximum. See our R 128 s1 explainer. If you are unsure what a term means, our loudness terms guide covers LUFS, LU, dBTP and LRA.
The practical rule: use the client’s sheet, and when it simply says “EBU R 128”, deliver at the target.
What about true peak and loudness range?
Clause m) sets the ceiling at -1 dBTP during production, measured with a meter that complies with ITU-R BS.1770 and EBU Tech 3341, with a measurement tolerance of plus or minus 0.3 dB for signals limited to 20 kHz. It also notes that lower ceilings may apply for different distribution systems and data-reduced formats, which is why some specs ask for -2 or -3 dBTP.
Loudness Range is not a pass or fail value in R 128 itself. Clause n) says it “may be used to evaluate the loudness variation of a programme”, and a footnote says that for programmes shorter than one minute, LRA is not recommended “due to too few data points”. If a client sheet sets an LRA limit, it comes from the client, not from R 128.
Check integrated loudness, true peak and LRA for every file in one run.
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How close to -23 LUFS should a delivered file be?
For file-based delivery, treat -23.0 LUFS as the number and the tolerances as protection, not targets. A sensible working routine:
- Measure the whole programme. Clause l) says the signal “shall generally be measured in its entirety, without emphasis on specific foreground elements such as speech, music or sound effects.”
- Apply gain to land on -23.0. A level change of 1 dB moves loudness by 1 LU, so the correction is simple arithmetic.
- Check true peak after gain. Raising a quiet mix can push peaks over -1 dBTP. Fix that with a true-peak limiter, not by giving back loudness. Our guide to fixing true peak overs explains why.
- Measure the delivered file again, not the session. Sample rate conversion, dither and encoding can all move the numbers slightly.
- Keep the measurement with the file. A report or BWF metadata settles questions later.
| Measured integrated loudness | Pre-recorded file | Live or as-live programme |
|---|---|---|
| -23.0 to -23.2 | At target within QC allowance | Fine |
| -22.5 | Correct it: 0.5 LU hot | Within tolerance, but should not become habit |
| -24.0 | Correct it: 1.0 LU quiet | At the edge of tolerance |
| -21.8 | Out of range | Out of range |
How does WavSpec handle R 128 deliveries?
WavSpec ships with a built-in EBU R 128 v5.0 broadcast spec, along with R 128 s1 short-form, UK DPP AS-11, ARD/ZDF/ORF TV (2025), ATSC A/85 (2026) and podcast and audiobook specs. According to its Microsoft Store listing, it:
- Measures integrated loudness, momentary and short-term maxima, loudness range, true peak and sample peak per ITU-R BS.1770-5 and EBU Tech 3341 and 3342.
- Corrects gain to the exact target, with look-ahead true-peak limiting using 4x oversampled detection, and converts sample rate and bit depth where the spec asks for it.
- Writes corrected files to a separate delivery folder, so originals are never overwritten, and re-measures every delivered file from disk.
- Produces a delivery report in PDF, HTML, CSV and JSON with before and after values, pass or fail per criterion and the SHA-256 of every delivered file, and writes verified loudness values into the bext chunk of Broadcast Wave files.
If a client asks for a tighter window than the built-in spec, or a different true peak ceiling, you can create your own named spec with its own fail and advisory rules and share it with colleagues as a file. Our R 128 normalisation page walks through a typical batch.
Frequently asked questions
Is -22.5 LUFS acceptable under EBU R 128?
For a live programme it is inside the plus or minus 1.0 LU tolerance. For a pre-recorded file that could have been corrected, it is off target, and a stricter broadcaster spec may reject it. Correct the gain and deliver at -23.0.
What is the 0.2 LU tolerance for?
It allows for small differences between compliant meters in quality control, so a file measured at -23.1 on one system is not failed because another reads -23.0. It is not extra headroom for the mix.
Did R 128 version 5 change the target or tolerance?
No. The November 2023 edition records only added references to R 128 s3, s4 and Tech 3401. The tolerance wording dates from earlier revisions.
Is LUFS the same as LKFS?
Yes. The EBU’s own footnote says LUFS is equivalent to LKFS, the name used in ITU-R BS.1770 and by ATSC.
Try WavSpec
WavSpec is a one-time purchase in the Microsoft Store with a free trial and a sample batch, so you can see a full run on first launch. All processing runs locally on Windows 11, with no account and no upload. More detail is on the WavSpec product page.
Deliver at -23.0 LUFS, not just near it, with a report for every file.
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EBU R 128 is published by the European Broadcasting Union. WavSpec is not affiliated with or endorsed by the EBU or any broadcaster.
Last updated 22 October 2026. Published by Automata Labs, a software company in Canada.