By Zencalcy Editorial TeamLast reviewed About us
Reverberation time is how long sound takes to decay by 60 dB after the source stops. The Sabine estimate uses room volume and total absorption, and it remains the standard first-pass calculation for halls, classrooms and studios. More absorption or a smaller volume shortens the tail.
Sabine reverberation time from room volume and absorption.
T₆₀ = 0.161 V / A
V is room volume in m³ and A the total absorption in sabins (m² of equivalent perfect absorber). The constant 0.161 assumes air absorption is negligible, which holds in the mid-frequency range.
| Symbol | Meaning |
|---|---|
| T₆₀ | Reverberation time in seconds. |
| V | Room volume. |
| A | Total absorption in sabins. |
T₆₀ = 0.161 × 100 / 20 = 0.805 s. Doubling the absorption to 40 sabins halves the reverberation time to 0.403 s.
Continue with the Sound Intensity Calculator, Sound Intensity Level Calculator, or the Sound Power Level Calculator — or browse more acoustics and sound tools and all physics calculators.
Sixty decibels is a practical dynamic range that spans most audible decays. Measuring the first 20 or 30 dB and extrapolating avoids the noise floor in real rooms.
Results are computed from the standard equations of classical mechanics. Unit conversions use the SI definitions published by NIST. Air resistance is ignored unless the calculator names a drag model.
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Last reviewed: September 2026. See how we build and check every tool on the about page.
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Content updated: September 2026