Reverb Time Sabine
Calculator
Results
- Reverberation time RT60 (s)
- 0.805
- Reverberation time RT60 (ms)
- 805
- Absorption needed for a 0.5 s RT60 (m²)
- 64.4
Music and audio results
| Reverberation time RT60 (s) | 0.805 |
| Reverberation time RT60 (ms) | 805 |
| Absorption needed for a 0.5 s RT60 (m²) | 64.4 |
formula-map diagram
- Reverberation time RT60 (s)
- 0.805
- Reverberation time RT60 (ms)
- 805
- Absorption needed for a 0.5 s RT60 (m²)
- 64.4
Musical and acoustic relationship
Formula
RT60 = 0.161 × V ÷ A= 0.805
Note
This result is a simplified model: it applies the displayed standard formula to the values you entered, assuming twelve-tone equal temperament, a speed of sound of 343 m/s in dry air at 20 °C, an ideal free field with no reflections or air absorption, purely resistive speaker loads and Sabine's diffuse-field assumption. Real rooms, instruments, codecs and amplifiers depart from these idealisations, so measure with proper instruments for critical work.
More in Music and audio
See all →Frequently asked questions
What does the Sabine formula calculate, and how does it work?+
Sabine's formula estimates RT60, the time for reverberant sound to decay by 60 dB, as RT60 = 0.161 x V / A, where V is the room volume in cubic meters and A is the total absorption (surface area multiplied by absorption coefficient, summed across all surfaces). A bigger, harder-surfaced room takes longer to decay.
Why does room volume increase reverb time while absorption decreases it?+
A larger volume means sound has to travel farther between reflections before losing energy, extending decay time, while more absorptive material converts more sound energy to heat on each reflection, shortening it. Reverb time is essentially a tug-of-war between how much space sound can bounce around in and how quickly the surfaces soak up that energy.
What counts as 'total absorption' in the formula?+
Total absorption sums each surface's area multiplied by its absorption coefficient (a value from 0, perfectly reflective, to 1, perfectly absorptive), added across walls, floor, ceiling, and any furniture or people present. A concrete wall might have a coefficient around 0.02, while thick carpet or acoustic foam can be 0.7 or higher.
Is the Sabine formula accurate for every type of room?+
It works best for rooms with fairly uniform absorption spread across surfaces and moderate absorption overall; highly absorptive rooms (like a padded vocal booth) or rooms with absorption concentrated on one surface tend to make Sabine's formula less accurate, and more advanced formulas like Eyring's are used instead. It's a solid first-pass estimate, not a lab-grade measurement.
What's a 'good' RT60 value for a space?+
It depends entirely on purpose: a small recording booth wants well under 0.3 seconds for a dry, controlled sound, a home theater or control room often targets around 0.3-0.5 seconds, and a concert hall for orchestral music might target 1.5-2+ seconds for a rich, sustained sound. There's no universal 'correct' number, only a target that fits the room's intended use.