Room Acoustics
RT60 Reverb Time Calculator
Enter your room dimensions and surface materials to calculate RT60 — the time it takes for sound to decay 60dB. Uses the Sabine equation, the industry standard for studio acoustic design.
How RT60 Is Calculated
The Sabine equation is: T60 = 0.161 × V / A
- V = room volume in cubic meters
- A = total absorption in m² sabins = Σ(surface area × absorption coefficient)
- 0.161 = constant (speed of sound at ~20°C)
Each surface is multiplied by its absorption coefficient α (0 = perfectly reflective, 1 = fully absorptive). Adding acoustic panels increases A, which reduces T60. This is why treatment lowers your room’s reverb tail.
RT60 Reference by Room Type
| Room type | Target RT60 | Notes |
|---|---|---|
| Vocal booth | 0.10 – 0.20 s | Extremely dry for clean isolation |
| Home studio control room | 0.15 – 0.35 s | Dead enough for accurate mixing |
| Professional tracking room | 0.25 – 0.50 s | Some natural room sound for live sessions |
| Live/drum room | 0.40 – 0.80 s | Adds character to live instruments |
| Small performance venue | 0.80 – 1.20 s | Enhances presence without muddiness |
| Large concert hall | 1.50 – 2.50 s | Designed for classical music, choir |
| Cathedral / large church | 3.00 – 8.00 s | Long, immersive reverb tail |
Frequently Asked Questions
What is RT60?
RT60 is the time it takes for sound in a room to decay by 60 decibels after the source stops. It is the standard measurement of reverberation time used in acoustics, studio design, and room treatment. A short RT60 (under 0.3 s) means a very dry, controlled room. A long RT60 (over 1.5 s) means a very live room like a concert hall or church.
What is the ideal RT60 for a home recording studio?
A home recording studio typically aims for RT60 between 0.15 and 0.35 seconds. This is dry enough to capture clean, uncolored recordings that translate well to different playback systems, while retaining just enough life to avoid an unnatural dead-box sound. Vocal booths can go even shorter at 0.10 to 0.20 seconds.
What is the Sabine equation?
The Sabine equation calculates RT60 as T60 = 0.161 × V / A, where V is the room volume in cubic meters and A is the total acoustic absorption in square meter sabins. It was developed by Wallace Clement Sabine at Harvard around 1900 and remains the primary formula used in room acoustics design and studio treatment planning.
What absorption coefficient does acoustic foam have?
Typical 2-inch acoustic foam panels have an absorption coefficient of around 0.50 to 0.65 at 1kHz. Thicker 4-inch foam panels improve low-frequency absorption and can reach 0.75 to 0.90 at 250Hz. By comparison, bare drywall absorbs only about 0.04 of sound energy at 1kHz, while heavy carpet absorbs around 0.50 to 0.60.