Room Mode Calculator

Calculate reverberation time (RT60) using the Sabine and Eyring equations. Input room dimensions and surface materials to get RT60, total absorption, and comparison to optimal values.

Inputs

Room length (m)

Room width (m)

Room height (m)

Room purpose (0-4)

Wall material (0-4)

Floor material (0-3)

Ceiling material (0-3)

Tab to move between fields

Results

RT60 Sabine (s)

2.88

RT60 Eyring (s)2.82

Optimal RT60 (s)0.6

RT60 vs optimal (s)2.28

Total absorption (m² Sabins)6.7

Average absorption coeff0.04

Room volume (m³)120

Schroeder frequency (Hz)310

How to Use This Calculator

Enter Room length (m), Room width (m), and Room height (m).
Set Room purpose (0-4), Wall material (0-4), and Floor material (0-3).
Adjust Ceiling material (0-3) as needed.
Review the RT60 Sabine (s) result.
Use RT60 Eyring (s) and Optimal RT60 (s) to inform your decision.

How the result changes with Room height (m)

Room height (m)	RT60 Sabine (s)
4.8	3.42
12	4.2
20	4.47
27	4.59

What each input means

Room length (m): Length of the room in meters.
Room width (m): Width of the room in meters.
Room height (m): Floor-to-ceiling height in meters.
Room purpose (0-4): 0 = Speech/classroom, 1 = Music rehearsal, 2 = Recording studio, 3 = Concert hall, 4 = Lecture hall.
Wall material (0-4): 0 = Concrete, 1 = Drywall, 2 = Wood panel, 3 = Acoustic panel, 4 = Heavy curtain.
Floor material (0-3): 0 = Concrete, 1 = Hardwood, 2 = Carpet on concrete, 3 = Heavy carpet with pad.
Ceiling material (0-3): 0 = Concrete, 1 = Drywall, 2 = Acoustic tile, 3 = Spray-on acoustical.

What each result means

RT60 Sabine (s): Reverberation time using Sabine equation: RT60 = 0.161 × V / A.
RT60 Eyring (s): Reverberation time using Eyring equation (more accurate for high absorption).
Optimal RT60 (s): Recommended RT60 for the selected room purpose.
RT60 vs optimal (s): Difference from optimal. Negative = too dry, positive = too reverberant.
Total absorption (m² Sabins): Total room absorption in metric Sabins (equivalent open-window area).
Average absorption coeff: Area-weighted average absorption coefficient of all room surfaces.
Room volume (m³): Calculated room volume.
Schroeder frequency (Hz): Below this frequency, room modes dominate; above, the sound field is diffuse.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Room length (m) = 8, Room width (m) = 5, Room height (m) = 3, Room purpose (0-4) = 0 = 7 input(s) provided
Calculate RT60 Sabine
RT60 Sabine = (0.161 * volume) / max(0.01, totalAbsorption)
2.884 = 2.884
Calculate RT60 Eyring
RT60 Eyring = avgAlpha < 0.99
2.822 = 2.822
Calculate Optimal RT60
Optimal RT60
0.6 = 0.6

Engine last updated July 11, 2026. Checked against 2 independently-derived tests — how we verify calculators.

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