LUFS measures perceived program loudness, while true peak estimates the highest reconstructed signal level. This guide explains how to calculate loudness adjustments, predict true peak, preserve headroom, and work with common streaming, podcast, and broadcast targets.
What Does LUFS Measure?
LUFS measures program loudness relative to digital full scale.
It is designed to provide a more useful representation of perceived loudness than a simple peak measurement. The measurement considers audio energy over time and applies frequency and channel weighting defined by the relevant loudness algorithm.
A more negative LUFS value represents quieter measured audio. A value closer to zero represents louder measured audio.
For example:
- −24 LUFS is quieter than −18 LUFS.
- −18 LUFS is quieter than −14 LUFS.
- −14 LUFS is quieter than −9 LUFS.
The difference between LUFS values is expressed in Loudness Units, or LU. For practical level adjustment, a difference of 1 LU corresponds to a 1 dB gain change.
Use the LUFS Loudness Calculator to calculate target gain, predicted loudness, true-peak headroom, and multi-track adjustments.
Why Peak Level Alone Is Not Enough
Peak level shows the highest signal level reached by the audio. It does not describe how much energy is present throughout the complete program.
Two recordings can have the same maximum peak but different perceived loudness.
A dynamic recording may contain short peaks with quieter material between them. A heavily compressed recording may remain near its peak level for much longer. Even when both recordings have the same peak, the compressed recording can measure substantially louder in LUFS.
This is why loudness and peak level should be measured separately.
Integrated, Short-Term, and Momentary Loudness
LUFS measurement can describe different time scales.
Integrated LUFS
Integrated LUFS represents average loudness across the complete measured program.
It is commonly used for:
- Songs
- Podcast episodes
- Finished videos
- Broadcast programs
- Audiobooks
- Advertisements
- Complete mixes
Integrated loudness should be measured across the entire file or the exact section intended for delivery.
Short-Term LUFS
Short-term LUFS represents loudness over a shorter moving period.
It helps identify changes between sections, such as:
- Loud music and quiet dialogue
- A podcast host and a guest
- A video introduction and main content
- A program and an advertisement
- Quiet verses and loud choruses
Short-term loudness should not be substituted automatically for integrated loudness because the two measurements cover different periods.
Momentary LUFS
Momentary loudness uses an even shorter measurement window.
It is useful for observing rapid changes while mixing, but it can move too quickly to represent the overall loudness of a complete program.
The Basic LUFS Gain Formula
For a linear gain adjustment:
Required Gain in dB = Target LUFS − Measured Integrated LUFS
Suppose a podcast measures −19 LUFS and the target is −16 LUFS:
−16 − (−19) = +3 dB
The theoretical adjustment is +3 dB.
If the same program measures −12 LUFS and the target is −16 LUFS:
−16 − (−12) = −4 dB
The theoretical adjustment is −4 dB.
The calculation predicts the effect of linear gain. Compression, limiting, clipping, editing, and encoding can change the final measurement.
Example: Increasing Loudness to a Target
Consider an audio file with:
- Integrated loudness: −20 LUFS
- Maximum true peak: −7 dBTP
- Target loudness: −16 LUFS
- True-peak ceiling: −1 dBTP
Calculate the required gain:
−16 − (−20) = +4 dB
Calculate the predicted true peak:
−7 + 4 = −3 dBTP
The predicted peak remains below the −1 dBTP ceiling.
The estimated result is:
- Gain adjustment: +4 dB
- Predicted integrated loudness: −16 LUFS
- Predicted true peak: −3 dBTP
Linear gain can theoretically reach the target without exceeding the selected ceiling.
Example: Reducing Loudness
Suppose a master measures:
- Integrated loudness: −9 LUFS
- Maximum true peak: −0.4 dBTP
- Target loudness: −14 LUFS
- True-peak ceiling: −1 dBTP
Required gain:
−14 − (−9) = −5 dB
Predicted true peak:
−0.4 − 5 = −5.4 dBTP
The estimated result is:
- Gain adjustment: −5 dB
- Predicted integrated loudness: −14 LUFS
- Predicted true peak: −5.4 dBTP
Attenuating the audio reduces both loudness and peak level.
How True-Peak Headroom Is Calculated
Positive gain increases true peak by the same number of decibels when no other processing is applied.
Available headroom is:
True-Peak Headroom = True-Peak Ceiling − Current True Peak
Suppose:
- Current true peak: −4 dBTP
- Ceiling: −1 dBTP
−1 − (−4) = +3 dB
The audio has 3 dB of available headroom before reaching the selected ceiling.
If the loudness target requires +5 dB, linear gain alone cannot reach the target while staying within that ceiling.
Peak-Safe Gain Formula
The calculator uses:
Peak-Safe Gain = Lower of Required Gain or Available Peak Headroom
Suppose:
- Current loudness: −19 LUFS
- Target loudness: −14 LUFS
- Current true peak: −3 dBTP
- Ceiling: −1 dBTP
Required gain:
−14 − (−19) = +5 dB
Available headroom:
−1 − (−3) = +2 dB
Peak-safe gain:
Lower of +5 dB and +2 dB = +2 dB
Predicted result:
- Loudness: −17 LUFS
- True peak: −1 dBTP
- Remaining loudness difference: −3 LU
Additional processing would be required to raise average loudness without allowing peaks to exceed the selected ceiling.
What Is True Peak?
True peak estimates the maximum level of the reconstructed waveform.
Digital audio stores individual samples, but playback and conversion reconstruct a continuous waveform between those samples. The reconstructed peak can be higher than the largest stored sample.
This is why a sample-peak meter and a true-peak meter can show different results.
True peak is normally displayed in dBTP. A measurement compatible with ITU-R BS.1770 should be used when evaluating loudness and true-peak compliance.
Sample Peak vs. True Peak
Sample Peak
Sample peak identifies the largest stored digital sample.
It is simple to calculate but may not reveal peaks between samples.
True Peak
True peak uses oversampling or a related reconstruction method to estimate the continuous waveform.
This helps identify potential inter-sample peaks that can become relevant during:
- Digital-to-analog conversion
- Sample-rate conversion
- Lossy encoding
- Playback processing
- Format conversion
When a delivery specification states a limit in dBTP, use a true-peak meter rather than a sample-peak meter.
Why True-Peak Headroom Matters
Audio close to digital full scale can produce unexpected overs when converted or encoded.
Leaving true-peak headroom can reduce the risk of:
- Clipping
- Codec overs
- Distortion
- Inter-sample peak problems
- Delivery rejection
- Inconsistent playback processing
The appropriate ceiling depends on the delivery specification and workflow.
LUFS vs. LKFS
LUFS means Loudness Units relative to Full Scale.
LKFS means Loudness, K-weighted, relative to Full Scale.
For ordinary numerical comparison in workflows based on the same loudness algorithm, the values are treated as equivalent.
A target of −24 LKFS corresponds numerically to −24 LUFS, although the terminology used may depend on the standard or organization.
LUFS vs. RMS
RMS measures average signal energy without applying the complete standardized loudness measurement process.
LUFS measurement includes features such as:
- Frequency weighting
- Channel weighting
- Time-based measurement windows
- Gating for integrated loudness
RMS can still be useful for technical analysis, but an RMS value cannot be substituted directly for a required LUFS measurement.
LUFS vs. dBFS
dBFS measures digital signal level relative to full scale.
LUFS measures program loudness.
A file can have a maximum sample peak of −1 dBFS while measuring −10 LUFS, −16 LUFS, or another integrated value depending on its dynamics and content.
Peak level does not determine integrated loudness by itself.
Converting a Gain Change to an Amplitude Multiplier
The formula is:
Amplitude Multiplier = 10^(Gain in dB ÷ 20)
Examples:
| Gain | Amplitude Multiplier |
|---|---|
| +1 dB | 1.122× |
| +2 dB | 1.259× |
| +3 dB | 1.413× |
| +6 dB | 1.995× |
| −1 dB | 0.891× |
| −3 dB | 0.708× |
| −6 dB | 0.501× |
A +6 dB change approximately doubles linear amplitude. It does not mean the audio will necessarily be perceived as exactly twice as loud.
Loudness Targets Are Delivery-Specific
There is no single LUFS target for every type of audio.
The appropriate target depends on:
- Streaming service
- Broadcaster
- Podcast workflow
- Client specification
- Region
- Playback setting
- Content type
- Dynamic range
- True-peak requirement
Always check the current destination requirements before final delivery.
Spotify Loudness Normalization
Spotify currently describes its Normal playback normalization level as −14 LUFS.
Normalization is applied during playback rather than permanently rewriting the uploaded master.
A loud master may receive negative gain during playback. A quiet master may receive positive gain when sufficient headroom is available.
Spotify also describes other playback normalization levels for eligible Premium settings. Playback behavior can vary by setting, device, and support for normalization.
A Spotify preset in a calculator is useful for estimating gain. It should not be treated as a mastering requirement that every file must hit exactly.
Podcast Loudness Targets
Podcast production often uses working targets such as −16 LUFS, but there is no universal target enforced by every podcast application, host, or distributor.
The appropriate choice may depend on:
- Mono or stereo production
- Spoken word or music-heavy content
- Network specification
- Advertising insertion
- Listening environment
- Dynamic range
- True-peak ceiling
Use the delivery requirements provided by the podcast network, client, host, or distributor when available.
EBU R128
EBU R128 recommends an average program loudness of −23 LUFS for applicable broadcast workflows.
It also uses loudness descriptors including:
- Program Loudness
- Loudness Range
- Maximum True Peak Level
The recommendation is designed for loudness normalization and consistent program exchange.
A simple calculator can estimate gain toward −23 LUFS, but complete R128 evaluation requires appropriate metering and consideration of all relevant descriptors.
ATSC A/85
ATSC A/85 addresses techniques for establishing and maintaining audio loudness for U.S. digital television workflows.
It is associated with a −24 LKFS target.
Broadcast delivery can involve requirements beyond integrated loudness, including metadata, measurement methods, program boundaries, and peak management.
Always follow the current specification supplied by the broadcaster or distributor.
Loudness Normalization vs. Mastering
Loudness normalization changes playback gain to bring measured audio toward a target.
Mastering is a creative and technical process that may include:
- Equalization
- Compression
- Limiting
- Saturation
- Stereo processing
- Sequencing
- Quality control
- Format preparation
Normalization does not repair an unbalanced mix, remove distortion, or restore lost dynamics.
A master should be evaluated for sound quality independently of the playback normalization target.
Why a Louder Master May Not Play Louder
If a platform normalizes playback loudness, a louder uploaded master can be turned down.
For example:
- Master A: −14 LUFS
- Master B: −9 LUFS
- Playback target: −14 LUFS
Master B may receive approximately 5 dB of negative playback gain.
It may not play louder than Master A after normalization. It may instead retain less dynamic range if heavy limiting was used to produce the louder master.
Why a Quiet Master May Not Reach the Target
A platform may be unable or unwilling to apply enough positive gain when the file lacks true-peak headroom.
Suppose:
- Integrated loudness: −20 LUFS
- True peak: −2 dBTP
- Playback target: −14 LUFS
- Intended peak headroom: −1 dBTP
The target requires +6 dB, but only 1 dB of headroom is available.
Raising the file by 6 dB without limiting would predict a true peak of +4 dBTP.
Playback systems may limit the increase, apply peak control, or handle the file differently according to their rules.
Why Limiting Changes the Predicted Result
The calculator assumes linear gain.
A limiter changes high-level peaks while leaving other parts of the program less affected. This changes the relationship between average loudness and peak level.
After limiting:
- The final LUFS may differ from the linear prediction.
- The true-peak value depends on limiter behavior.
- Loudness range may change.
- Distortion may increase.
- Codec conversion may produce new peaks.
Measure the output again after processing.
Compression and Integrated Loudness
Compression reduces the difference between louder and quieter parts of a signal according to its settings.
Makeup gain can then raise the overall level while controlled peaks remain lower than they would under linear gain alone.
The result depends on:
- Threshold
- Ratio
- Attack
- Release
- Knee
- Sidechain filtering
- Makeup gain
- Program material
There is no single formula that predicts the final LUFS of every compressed signal from these settings alone.
Comparing Multiple Tracks
When preparing an album, podcast series, course, or video package, track-to-track loudness consistency can be evaluated by comparing integrated measurements.
For a −16 LUFS target:
| Track | Measured LUFS | Linear Adjustment |
|---|---|---|
| Track 1 | −13 LUFS | −3 dB |
| Track 2 | −16 LUFS | 0 dB |
| Track 3 | −18 LUFS | +2 dB |
| Track 4 | −21 LUFS | +5 dB |
Each positive adjustment must also be checked against that track’s own true-peak measurement.
The calculator’s comparison section shows target differences, but individual true-peak evaluation remains necessary.
Album Normalization vs. Track Normalization
Track normalization evaluates each track independently.
Album normalization can preserve intentional loudness differences between tracks by applying a consistent gain relationship across the album.
Independent track normalization may make a quiet interlude as loud as an intentionally powerful track, altering the artistic sequence.
When preparing an album or connected program, confirm whether the destination uses track-based or album-based playback normalization.
Recommended Loudness Workflow
Measure the Unprocessed or Current Master
Use an ITU-R BS.1770-compatible loudness meter.
Record:
- Integrated LUFS
- Maximum true peak
- Optional short-term loudness
- Optional Loudness Range
Confirm the Destination
Identify the current loudness and peak requirements for the delivery platform, broadcaster, client, or network.
Calculate the Linear Adjustment
Subtract measured loudness from the target.
Check True-Peak Headroom
Determine whether the required positive gain fits below the selected ceiling.
Decide Whether Processing Is Needed
If linear gain cannot reach the target safely, evaluate the mix, compression, limiting, or target choice.
Export the Final Audio
Use the required sample rate, bit depth, channel format, codec, and container.
Measure the Final Export
Do not rely only on the pre-export session meter. Measure the delivered file after all processing and encoding.
Common LUFS Mistakes
Measuring Only the Loudest Section
Integrated loudness should cover the complete program intended for delivery.
Using Short-Term LUFS as the Final Integrated Value
Short-term loudness represents a shorter window and can change rapidly.
Confusing True Peak with Sample Peak
Use the measurement requested by the delivery specification.
Applying Positive Gain Without Checking Headroom
Loudness and peaks rise together under linear gain.
Treating Every Suggested Target as Mandatory
Some values are platform normalization references or common working targets rather than universal upload requirements.
Mastering Only to a Number
A technically matched LUFS value does not guarantee clarity, balance, dynamics, or sound quality.
Forgetting to Measure After Encoding
Lossy encoding and sample-rate conversion can change peak behavior.
Assuming Normalization Is Active Everywhere
Playback behavior can vary by device, application, account setting, and platform support.
Practical Quality-Control Checklist
Before delivery, verify:
- The complete program was measured.
- Integrated LUFS uses the required algorithm.
- Maximum true peak was measured.
- The current destination specification was checked.
- Positive gain does not exceed available headroom.
- Limiting is not causing unacceptable distortion.
- Dialogue remains intelligible.
- Music retains appropriate dynamics.
- Multiple tracks sound consistent where intended.
- The final encoded file was measured.
- File format and channel layout are correct.
- Playback was checked on suitable monitoring equipment.
Frequently Asked Questions
How do I calculate the gain required for a LUFS target?
Use:
Target LUFS − Measured LUFS = Required Gain in dB
What gain moves −18 LUFS to −14 LUFS?
−14 − (−18) = +4 dB
Check true-peak headroom before applying the complete increase.
What gain moves −10 LUFS to −14 LUFS?
−14 − (−10) = −4 dB
Can I calculate LUFS from true peak?
No. True peak does not contain enough information to determine integrated loudness.
Can I calculate LUFS without analyzing audio?
No. A loudness meter must analyze the audio first. The calculator works with the measured result.
Is −14 LUFS required for every music master?
No. It is a normalization reference used in certain playback contexts, not a universal mastering requirement.
What happens if true peak exceeds the ceiling?
The audio may require attenuation, limiting, remixing, or another processing decision. The appropriate response depends on the delivery requirements and desired sound.
Does lowering LUFS reduce audio quality?
Linear attenuation does not inherently damage the signal. Excessive compression, limiting, clipping, or repeated encoding can affect quality.
Why does my loudness meter show a different result?
Possible causes include different standards, gating, measurement periods, channel handling, meter settings, program boundaries, or software implementations.
Does OutputMath upload my audio?
No. The calculator does not accept an audio file. Measurements and calculation history remain in the browser.
Final Takeaway
The basic loudness adjustment is:
Required Gain = Target LUFS − Measured Integrated LUFS
Positive gain must be checked against available true-peak headroom:
Peak Headroom = Ceiling − Current True Peak
A calculator can predict linear gain results, but it cannot replace final measurement. Compression, limiting, editing, encoding, and playback normalization can change loudness and peak values.
Use the LUFS Loudness Calculator to estimate target gain, peak-safe gain, predicted LUFS, predicted true peak, amplitude multiplier, and multi-track adjustments.