RT60 Reverberation Calculator | FreeAcoustics.tools

What is RT60?

RT60 (Reverberation Time) measures how long sound takes to decay by 60 dB after the source stops — essentially how long a room "rings." It determines whether a space sounds live and echoey or dead and controlled.

Target values vary by use: Recording studios need short RT60 (0.25-0.3s) for clarity. Classrooms need moderate (0.4-0.6s) for speech intelligibility. Concert halls need longer (1.5-2s) for musical richness. This calculator helps you determine how much acoustic treatment you need.

Room Dimensions

Length ?

Width ?

Height ?

Calculation Method ⓘ

Analysis Frequency

Surface Materials ?

Absorption Distribution 0 sabins

—

Surface Material Area α Sabins

Formula Reference

RT₆₀ = 0.049 × V / A

Sabine: RT₆₀ = kV/A where k = 0.049 (ft) or 0.161 (m)
Eyring: RT₆₀ = kV / (-S × ln(1-ᾱ))

V = volume, A = total absorption (sabins), S = total surface area, ᾱ = average absorption coefficient

Sources: ISO 3382-1:2009, Sengpiel Audio, ScienceDirect

Target Room Type

Calculated RT60 @ 500 Hz

0.00

seconds

Using Sabine formula

Target: 0.3s —

Room Volume

4,500 ft³

Total Surface

2,060 ft²

Total Sabins

Avg. α

0.00

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