Room Acoustic Calculator

Calculate RT60 reverberation time for any room in seconds. Get instant product recommendations based on your dimensions, surface type, and room use.

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Reverberation Time (RT60)

The ambient soundscape of an auditorium or room directly impacts how sound is perceived. The reverberant sound in an auditorium dies away with time as the sound energy is absorbed by multiple interactions with the surfaces of the room.

Live Room: In a more reflective room, it will take longer for the sound to die away.

Acoustically Dead Room: In a very absorbent room, the sound will die away quickly, ensuring high clarity.

Why 60 dB? (The Rationale)

The time for reverberation to completely die away depends upon how loud the sound was to begin with, and the acuity of the hearing of the observer. To provide a reproducible parameter independent of the initial test sound intensity, a standard reverberation time has been defined as the time for the sound to die away to a level 60 decibels below its original level (RT60).

The 60 dB Rationale: The loudest crescendo for most orchestral music is about 100 dB, and a typical room background noise level for a good music-making area is about 40 dB. Thus, the standard reverberation time (RT60) is precisely the time it takes for the loudest musical peak to decay down to the quiet background level of the room.

What is a Desirable Reverberation Time?

The optimum reverberation time strongly depends upon the room’s intended purpose and its volume, as modeled by the Sabine Formula:

$$RT_{60} = \frac{0.161 \cdot V}{S_e}$$

(Where $V$ is the room volume and $S_e$ is the effective absorbing area).

Venue Type	Desirable Reverberation Time
Recording Studios	Minimized (As short as possible for maximum recording clarity)
Classrooms	Very short (Less than 1.0 second for speech intelligibility)
General Purpose Auditoriums	Around 2.0 seconds (Balanced for both speech and music)

World-Class Examples of RT60

Some of the most acoustically famous concert halls in the world utilize specific reverberation times to achieve their legendary sound quality:

Venue	Reverberation Time
Vienna, Musikvereinsaal	2.05 seconds
Boston, Symphony Hall	1.8 seconds
New York, Carnegie Hall	1.7 seconds

Note: The overall average reverberation time is only part of the architecture; the variation of reverberation time across different sound frequencies is equally essential for true acoustic balancing.

Room Treatment Calculator Data

To calculate your approximate reverberation time, the following parameters are required for our engineering analysis:

Room Dimensions: Height ($H$), Length ($L$), Width ($W$) to determine total Volume ($V$).
Absorption Coefficients ($\alpha$): Evaluated separately for the Walls ($\alpha_{walls}$), Floor ($\alpha_{floor}$), and Ceiling ($\alpha_{ceiling}$) to establish the Average Coefficient ($\alpha_{avg}$) and Effective Absorbing Area ($S_e$).